Multi-State Tax Compliance: The Complete Guide for Growing Florida Businesses

Last Updated: December 2025

Introduction

Six months after your Florida-based e-commerce business started shipping nationwide, you get a letter from California’s Franchise Tax Board. They’ve noticed your sales activity in their state and want to know why you haven’t registered to collect sales tax. The penalties? They’re calculating back taxes, interest, and late filing penalties that could total tens of thousands of dollars.

This scenario plays out every day for growing businesses. You started in Florida, took advantage of the state’s business-friendly environment and lack of income tax, and focused on what you do best: building your company. But the moment you cross state lines—whether physically or digitally—everything changes.

The 2018 Supreme Court decision in South Dakota v. Wayfair fundamentally transformed how states can tax out-of-state businesses. Before Wayfair, you generally needed a physical presence in a state to owe taxes there. After Wayfair, economic activity alone—selling products or services to customers in a state—can create tax obligations. For small businesses, this meant going from potentially owing taxes in one or two states to suddenly having obligations in twenty or more.

The Cost of Non-Compliance Is Real

We’re not talking about minor penalties. States are aggressive about collecting tax revenue, and the consequences of non-compliance include:

Back taxes for every year you’ve been out of compliance (typically up to 3-4 years, sometimes more)
Penalty fees ranging from 5% to 25% of taxes owed
Interest that compounds monthly
Legal fees if you need to contest assessments
In extreme cases, personal liability for business owners
Damage to your business reputation and credit

But here’s the thing: most business owners who find themselves in this situation weren’t trying to avoid their obligations. They simply didn’t know they had them.

Who This Guide Is For

This comprehensive guide is designed for Florida-based entrepreneurs and growing businesses who are:

Selling products or services to customers in other states
Building remote teams with employees living outside Florida
Expanding physically with offices, warehouses, or stores in other states
Working on projects or contracts that take you beyond Florida’s borders
Using fulfillment services like Amazon FBA that store inventory nationwide
Growing rapidly and wondering when multi-state obligations kick in

Whether you’re doing $100,000 or $10 million in revenue, if you’re conducting business beyond Florida’s borders, this guide will help you understand your obligations and make informed decisions about compliance.

We’ll walk through the critical concepts, break down common scenarios, and help you understand when DIY compliance is feasible and when professional help becomes not just helpful, but essential.

Chapter 1: Understanding Nexus – When Do You Owe Taxes in Another State?

The foundation of multi-state taxation is a concept called “nexus.” Understanding nexus is critical because it determines whether you have tax obligations in a given state. Get this wrong, and you could either be filing unnecessarily in states where you have no obligation, or—more commonly—failing to file in states where you do.

What Is Nexus?

In plain English, nexus is the connection between your business and a state that creates a tax obligation. Think of it as the threshold that, once crossed, means you owe that state either sales tax, income tax, or both.

Before 2018, nexus was primarily about physical presence. If you had a store, office, or employees in a state, you had nexus. If you were just selling to customers in that state from your Florida headquarters, you generally didn’t.

The Wayfair decision changed this by establishing “economic nexus”—the principle that substantial economic activity in a state, even without physical presence, can create tax obligations. This decision opened the floodgates for states to require out-of-state businesses to collect sales tax.

Types of Nexus

There are two main types of nexus you need to understand:

Physical Nexus

Physical nexus is created when you have a tangible presence in a state. This includes:

Offices, stores, or warehouses: Even a small shared office space or storage unit can create nexus
Employees: If you have employees working in a state, even remotely from their homes, you have nexus there
Inventory: Goods stored in a state create nexus—this is critical for businesses using Amazon FBA or third-party warehouses
Independent contractors: Contractors working on your behalf in a state can create nexus
Attending trade shows or events: Even temporary presence can trigger obligations in some states
Company vehicles: Regularly operating vehicles in a state may create nexus
Property ownership: Owning any property in a state creates nexus

Physical nexus typically creates both sales tax and income tax obligations immediately.

Economic Nexus

Economic nexus is based purely on sales volume or transaction count in a state, regardless of physical presence. After the Wayfair decision, states rushed to establish their own economic nexus thresholds.

Most states follow a pattern of requiring registration once you exceed:

$100,000 in gross sales to customers in that state, OR
200 separate transactions in that state

However, there are variations:

Some states use $100,000 only (no transaction count)
Some use $500,000 as their threshold
California requires $500,000 in sales
Texas requires $500,000 in sales
A few states have lower thresholds

Economic nexus primarily creates sales tax obligations, though some states have extended the concept to income tax as well (called “factor presence nexus”).

Common Nexus Triggers Florida Businesses Miss

Based on our experience working with growing businesses, here are the nexus triggers that catch entrepreneurs off guard:

Remote Employees

This is the number one surprise. You hire a great developer who lives in North Carolina. Congratulations—you now have nexus in North Carolina and need to register for payroll taxes, withhold state income tax, pay unemployment insurance, and potentially file corporate income tax returns there. Many business owners assume that because they’re a Florida company, they only deal with Florida taxes. That’s not how it works.

Amazon FBA and Third-Party Fulfillment

When you use Fulfillment by Amazon, your inventory is stored in Amazon’s warehouses across the country. Amazon moves your inventory between facilities based on their logistics algorithms. You might think your inventory is in one state, but Amazon could have distributed it to six states to optimize shipping times.

Each state where your inventory sits creates physical nexus. This means many FBA sellers have nexus in 10+ states without realizing it. Amazon provides reports showing where your inventory is located, but many sellers don’t check these regularly or understand the implications.

Drop-Shipping Arrangements

If you’re using drop-shipping—where your supplier ships directly to your customer—the nexus rules get complicated. Who has the tax obligation? Generally, you do as the retailer, but the specific arrangements and state rules matter. Some states look at where the supplier ships from, others look at where you’re established.

Affiliate Marketing Programs

Some states have “click-through nexus” rules. If you have affiliates or partners in a state promoting your products, and those relationships generate significant sales, you may have created nexus there. New York pioneered these rules, and other states have followed.

Services Performed in Other States

If you’re a consulting firm, contractor, or service provider and you physically perform work in another state, you’ve likely created nexus. A Florida-based contractor doing a three-month project in Georgia needs to understand Georgia tax obligations.

Inventory “In Transit”

Here’s an obscure one: some states claim nexus if your goods are merely passing through their state, even in a common carrier’s vehicle. Most states don’t enforce this aggressively, but it shows how complex the rules can get.

Trade Shows and Temporary Events

Attending a trade show in another state can create nexus, though many states provide exemptions for temporary or occasional presence. The rules vary significantly by state and the duration of your presence.

The challenge isn’t just understanding what creates nexus—it’s tracking all these variables as your business grows. What starts as a simple Florida business can quickly become a multi-state compliance challenge.

Key Takeaway: If you’re doing business beyond Florida’s borders in any form—selling, employing, or storing goods—you likely have nexus somewhere. The question isn’t whether you have multi-state obligations, but how many states you’re obligated to.

Chapter 2: Sales Tax Compliance Across State Lines

Sales tax is where most growing businesses first encounter multi-state compliance challenges. Unlike income tax, which might only apply if you’re profitable, sales tax obligations kick in as soon as you cross nexus thresholds—even if your business is losing money.

When Florida Businesses Must Collect Sales Tax Elsewhere

The trigger for sales tax obligations is nexus (which we covered in Chapter 1) plus taxable sales. Here’s how to know when you need to start collecting:

Economic Nexus Thresholds

Each state sets its own economic nexus threshold for sales tax. Most follow the $100,000 or 200-transaction standard, but there are variations:

$100,000 threshold: Most states including Georgia, North Carolina, Tennessee, Alabama, Mississippi
$500,000 threshold: California, New York, Texas
No transaction count: Many states dropped the 200-transaction requirement and use sales only
Different rules for marketplace sales: Some states treat marketplace sales (Amazon, eBay) differently

You need to track your sales by destination state (where your customer is located, not where they’re billed) and monitor when you cross these thresholds.

What Counts Toward the Threshold?

Generally, your total gross sales to a state count toward the nexus threshold, including:

Taxable product sales
Non-taxable product sales
Some states include shipping charges
Some states include sales made through marketplaces

However, once you’re required to register, you only collect tax on taxable sales. What’s taxable varies by state and product category.

Timing: When Do You Need to Register?

Most states require registration once you’ve exceeded their threshold. Some states provide a grace period or require you to register prospectively (after you cross the threshold, you register for next year). But many states expect you to register immediately once you’ve crossed the threshold, meaning you may already be late by the time you realize it.

Our recommendation: Register as soon as you know you’ll exceed a state’s threshold in the current calendar year. Don’t wait until December 31st.

What You’re Actually Selling Matters

Not all sales are created equal when it comes to sales tax:

Physical Products

Generally taxable in most states, with exceptions:

Groceries (tax treatment varies by state)
Clothing (not taxable in some states, taxable in others)
Prescription medications (usually exempt)
Medical devices (often exempt)

Digital Products

This is where it gets messy. States don’t agree on how to tax digital goods:

E-books, digital music, streaming services: taxable in some states, not in others
SaaS (Software as a Service): treated as a taxable service in some states, non-taxable in others
Downloaded software: different from SaaS in some states’ eyes
Digital art, NFTs: emerging area with unclear rules

Services

Florida doesn’t tax most services, which can lull Florida business owners into thinking services aren’t taxable. But many other states DO tax services:

Personal services (haircuts, spa services): often taxable
Digital services (web design, graphic design): varies widely
Consulting services: generally not taxable, but some exceptions exist
Installation and repair: often taxable
Professional services (accounting, legal): generally not taxable

You need to research each state’s rules for your specific type of product or service.

Marketplace Facilitator Rules

Here’s one area where things got easier: marketplace facilitator laws.

What This Means

When you sell through Amazon, Etsy, eBay, or other online marketplaces, the marketplace itself is now responsible for collecting and remitting sales tax in most states. This is a huge administrative relief.

When You’re Still Responsible

However, you remain responsible for:

Sales made through your own website or direct channels
Sales through marketplaces in states that don’t have marketplace facilitator laws (rare but exists)
Proper record-keeping and reporting, even when the marketplace collects tax
Ensuring the marketplace is actually collecting tax correctly

Hybrid Models

If you sell both direct and through marketplaces, you need to:

Track each channel separately
Register in states where your direct sales create nexus
Understand that marketplace sales still count toward economic nexus thresholds
Maintain documentation for audits

The Registration Process

Once you’ve determined you need to register, here’s what to expect:

General Process

Gather your business information: EIN, formation documents, ownership details
Go to the state’s department of revenue website
Complete the sales tax registration application
Some states require bonds (especially if you’re registering with back-tax liability)
Receive your sales tax permit/license
Set up your filing schedule (monthly, quarterly, or annual)

Documents You’ll Need

Federal EIN
Business formation documents (Articles of Organization/Incorporation)
Florida sales tax permit (if applicable)
NAICS code for your business
Estimated monthly sales by state
Banking information for electronic payments

Timeline Expectations

Some states process immediately (online applications)
Others take 2-6 weeks
If bonds are required, add additional time
Plan ahead—you can’t collect tax until you’re registered

Costs

Most states: Free to register
Some states: Small registration fees ($5-$50)
Bond requirements: Varies based on expected tax liability, can be hundreds to thousands of dollars
Voluntary disclosure programs: May involve professional fees

The Voluntary Disclosure Option

If you realize you should have been registered but weren’t, you may want to consider a Voluntary Disclosure Agreement (VDA). This is a formal program most states offer where you come forward, admit non-compliance, and often receive:

Reduced look-back periods (3 years instead of 6-10)
Penalty waivers
Sometimes interest waivers
Anonymity during the negotiation process

VDAs are complex and almost always require professional representation, but they can save significant money if you have substantial back-tax exposure.

Ongoing Compliance

Registering is just the beginning. Ongoing compliance requires:

Filing Frequency

States assign filing frequencies based on your expected tax liability:

Monthly: Higher volume sellers
Quarterly: Mid-volume sellers
Annual: Low-volume sellers

You must file on time even if you have zero sales (zero-dollar returns).

What You’re Filing

Sales tax returns typically require:

Gross sales in the state
Taxable sales
Exempt sales (with explanation)
Tax collected
Any deductions or credits
Payment of tax due

State-by-State Differences

Every state’s return is different. Some are simple (one page), others are complex (multiple schedules for different tax types). You’ll need to:

Learn each state’s specific requirements
Understand their filing deadlines (not all use the same monthly dates)
Know their payment methods
Keep up with rule changes

What Happens If You File Late

Penalties for late filing typically include:

Late filing penalty (5-25% of tax due)
Late payment penalty (additional percentage)
Interest on unpaid tax (compounds monthly)
In extreme cases, criminal penalties

Many states have amnesty programs periodically, but you can’t rely on those.

Zero-Dollar Returns

Even if you had no sales in a state during a filing period, you still must file a return in most states. Failing to file zero-dollar returns can result in penalties and may trigger audits.

Important Reality Check: Managing sales tax compliance across multiple states is time-consuming and detail-oriented work. A business with nexus in 20 states could be filing 60+ sales tax returns per year (monthly filers) or 80+ returns (quarterly filers with different schedules). This is before we even discuss income tax.

Chapter 3: Income Tax – When Your Florida Advantage Disappears

One of the greatest advantages of operating a business in Florida is the absence of state income tax. No corporate income tax, no personal income tax. It’s a significant benefit that keeps many businesses here.

But the moment you expand beyond Florida’s borders, that advantage becomes limited. Other states will want their share of your income, and navigating multi-state income tax is considerably more complex than sales tax.

Florida’s No-Income-Tax Benefit (And Its Limits)

The Florida Advantage

For a Florida-only business:

No state corporate income tax
No personal income tax for owners
Simplified tax filing (federal only)
More money stays in the business or your pocket

This is why many entrepreneurs choose Florida as their base.

Where the Advantage Stops

The moment you have nexus in another state (through employees, offices, or economic activity), that state can tax the portion of your income that’s attributable to activities in their state. Florida’s lack of income tax doesn’t protect you from other states’ income taxes.

This is particularly relevant for:

S-Corporations and LLCs: Owners pay personal income tax in states where the business has nexus
C-Corporations: May owe corporate income tax in each state where there’s nexus
Partnerships: Partners may owe tax in each state where the partnership operates

When You Owe Income Tax in Other States

Physical Presence Creates Immediate Obligation

If you have any of the following in a state, you likely owe income tax there:

An office or place of business
Employees working in that state
Owned or leased property
Inventory stored there

Economic Nexus for Income Tax

Some states have adopted “factor presence nexus” standards for income tax, similar to economic nexus for sales tax. These typically look at:

Property value in the state
Payroll in the state
Sales into the state

If you exceed certain thresholds (commonly $50,000-$100,000 in any factor), you may owe income tax even without physical presence. This is less common than sales tax economic nexus but growing.

Temporary Projects

If you’re a contractor or consultant doing work in another state, even temporarily, you may create income tax nexus. Many states have thresholds (like working 15+ days in the state) before nexus is created, but these vary.

Apportionment – How States Divide Your Income

Here’s where multi-state income taxation gets really complex. If your business operates in multiple states, how do you determine how much income each state can tax?

The Apportionment Formula

States use apportionment formulas to divide your total business income among the states where you operate. The historical standard was the three-factor formula:

Property Factor: The value of property you own or rent in each state
Payroll Factor: Wages paid to employees in each state
Sales Factor: Sales made to customers in each state

Each factor is calculated as a percentage (your property in State A / your total property everywhere), then the three factors are averaged to determine what percentage of your income State A can tax.

Example:

Your Florida business has 50% of its property in FL, 50% in Georgia
You have 60% of your payroll in FL, 40% in Georgia
You have 70% of your sales in FL, 30% in Georgia

Georgia’s apportionment percentage: (50% + 40% + 30%) / 3 = 40%

If your business has $100,000 in taxable income, Georgia would tax $40,000 of it.

Single Sales Factor States

Many states now use single sales factor apportionment, meaning they only look at where your sales are made. This is more favorable for businesses with property and employees in the state but sales elsewhere, and less favorable for businesses with sales in the state but operations elsewhere.

Market-Based Sourcing

Complicating things further, states have different rules for determining where a sale occurs:

Cost of performance: Where you performed the work (traditional)
Market-based sourcing: Where the customer receives the benefit (increasingly common)

This particularly matters for service businesses. If you’re a Florida-based consultant serving a California client, does that count as a Florida sale or California sale? The answer depends on each state’s sourcing rules.

Why This Gets Complicated Fast

Consider a Florida business with:

Headquarters in Florida
Warehouse in Georgia
Employees working remotely in Texas, North Carolina, and Virginia
Customers nationwide

You’d need to:

Track property values in FL and GA
Calculate payroll percentages in five states
Determine sales sourcing for each transaction
Apply different apportionment formulas for different states
File income tax returns in multiple states
Deal with “nowhere income” situations (income not taxed anywhere due to formula differences)

State-Specific Considerations

States With No Income Tax

Good news: several states have no income tax, including:

Texas
Tennessee (limited tax on interest and dividends only, being phased out)
Nevada
Washington
Wyoming
South Dakota

However, these states may have other taxes:

Texas: Franchise tax (gross receipts-based)
Washington: Business & Occupation tax
Nevada: Commerce tax for larger businesses

States With High Income Tax Rates

Be aware of states with particularly high corporate or personal income tax rates:

California: 8.84% corporate, up to 13.3% personal
New York: 6.5% corporate, up to 10.9% personal
New Jersey: 9% corporate, up to 10.75% personal

Kentucky Considerations

Since Milbrod & Hessel has an office in Kentucky, it’s worth noting:

Kentucky corporate income tax: 5%
Kentucky uses single sales factor apportionment
Has its own set of nexus standards and requirements
Requires both state and local tax considerations in some areas

Entity Structure Matters

Your business structure significantly affects how multi-state income tax works:

C-Corporations

File corporate income tax returns in each state where you have nexus
Pay state corporate income tax rates (typically 3-10%)
Shareholders only deal with multi-state tax when they receive dividends
Double taxation exists (corporate level + personal level)

S-Corporations

File composite or individual returns in each state
Income flows through to shareholders, who pay personal income tax
Each shareholder may need to file personal returns in each state where the S-Corp has nexus
More complex for shareholders but avoids double taxation

LLCs (Taxed as Partnerships)

Partnership files returns in each nexus state
Each partner receives K-1 showing their share of income by state
Each partner files personal returns in relevant states
Most flexible but can be administratively complex

Single-Member LLCs

Treated as disregarded entities for federal tax (income on owner’s personal return)
Some states require separate LLC filings
Simpler than partnerships but still requires multi-state attention

Choosing the Right Structure

Multi-state operations should influence your entity structure decisions:

Where will your business operate?
Where do your owners live?
What’s your growth trajectory?
How much complexity can you manage?

These are questions best addressed with a CPA who understands multi-state taxation before you make entity structure decisions.

The Professional Guidance Reality: Most small business owners can handle a Florida-only tax return. Multi-state apportionment? That’s where mistakes get expensive. The rules are complex, they change frequently, and getting them wrong means either paying too much tax (bad for you) or too little (bad when you get audited).

Chapter 4: Employment Tax and Remote Workers

The shift to remote work has been one of the biggest changes in how businesses operate over the past several years. For Florida businesses hiring talent from anywhere, it’s a competitive advantage. But it also creates significant multi-state tax complexity that many employers don’t anticipate.

The Remote Work Revolution and Tax Implications

The New Normal

Hiring a great employee shouldn’t be limited by geography. Many Florida businesses now have employees working from homes across the country. This is fantastic for accessing talent, but here’s the reality: where your employee lives determines where you have payroll tax obligations.

One employee in California doesn’t just mean you’re employing someone in California. It means:

Registering as an employer in California
Withholding California state income tax
Paying California unemployment insurance
Complying with California wage and hour laws
Potentially owing California corporate income tax
Providing required California employment notices and benefits

Multiply this by five employees in five states, and you can see how complexity multiplies quickly.

“Convenience of Employer” Rules

Some states have particularly aggressive rules. New York and Nebraska, for example, have “convenience of employer” rules. These states say that if you’re working remotely for convenience (yours or the employer’s), not because the employer requires it, your income is still taxable by the state where the employer is located.

This can create situations where:

Your Florida business hires a New York employee who moves to Florida
New York claims they’re only in Florida for “convenience”
New York tries to tax that employee’s income even though they now live in Florida

These rules are controversial and subject to legal challenges, but they exist.

Withholding Requirements

State Income Tax Withholding

When you have an employee in a state with income tax, you must:

Register with that state’s department of revenue or taxation
Obtain employer withholding account numbers
Have employees complete that state’s equivalent of a W-4
Calculate and withhold the correct amount based on that state’s rates and brackets
Remit withheld taxes on that state’s schedule (monthly, quarterly, etc.)
File quarterly reconciliation returns
Provide W-2s that properly report state wages and withholding

Every state has different:

Tax rates and brackets
Withholding calculation methods
Filing frequencies and deadlines
Forms and reporting requirements

Multiple States, One Employee

What if an employee works in multiple states? Some possibilities:

A traveling salesperson who works in their home state plus visits clients in other states
An employee who moves mid-year from one state to another
Someone who splits time between states (snowbirds, for example)

You may need to:

Allocate wages between states
Withhold for multiple states
Understand reciprocity agreements between states
Track days worked in each location

Quarterly Filings

Most states require quarterly reconciliation returns where you report:

Total wages paid
Total withholding
Any adjustments
Payment of amounts due

Miss these deadlines, and penalties accrue quickly.

Year-End Reconciliation

At year-end, you must:

File annual reconciliation returns in each state
Provide W-2s to employees with proper state information
Submit W-2 copies to each state
Ensure everything balances across federal and state returns

Unemployment Insurance

SUTA (State Unemployment Tax)

Every state operates its own unemployment insurance program (except for Wyoming, which uses a hybrid model). When you have employees in a state, you must:

Register with that state’s unemployment insurance agency
Pay quarterly unemployment taxes based on your payroll in that state
File quarterly wage reports listing each employee and their wages
Maintain compliance even if you have just one employee in the state

Experience Rating

States assign unemployment tax rates based on your “experience rating”—essentially, how many former employees have filed unemployment claims against you. New employers start at a base rate, then rates adjust based on claim history.

When you’re new to a state, you’ll pay new employer rates, which can be higher than established employer rates. This varies by state.

Multi-State Complications

If an employee works in multiple states, there are rules for determining which state’s unemployment insurance applies. Generally, it’s based on:

Where the employee primarily works
Where they’re directed/controlled from
Specific interstate agreements

Quarterly Wage Reports

Each quarter, you must report:

Each employee who worked in the state
Their total wages
Calculate and pay unemployment tax
Keep records of all filings

Workers’ Compensation

State Requirements

Most states require workers’ compensation insurance for employees. When you have remote employees:

You need coverage in each state where you have employees
Some states allow one policy to cover all states
Others require separate state-specific policies
Requirements and costs vary significantly by state

Coverage Considerations

Workers’ compensation for remote employees raises questions:

If an employee is injured while working from home, is it covered?
What if they’re injured while traveling for work?
How do you verify home office safety?

These are emerging issues as remote work becomes permanent.

Local Taxes (Yes, There’s More)

Some states have city or county income taxes that add another layer:

Ohio: Many cities have local income tax (ranging from 0.5% to 3%) Pennsylvania: Local income taxes in many municipalities Kentucky: Some cities have occupational taxes Indiana: County-level income taxes Maryland: County taxes on top of state tax

If you have an employee in Cincinnati, Ohio, you’re not just dealing with Ohio state tax—you’re also dealing with Cincinnati city tax. Each locality has its own:

Registration requirements
Filing deadlines
Forms and procedures
Rates and calculation methods

The Reality Check: If you have employees in five states, you’re potentially managing:

5 state income tax withholding accounts
5 state unemployment insurance accounts
5 workers’ compensation policies
Multiple local tax accounts
20+ quarterly filings
5+ annual reconciliations
Ongoing compliance monitoring

And this is all before we talk about your corporate income tax obligations in those same states.

Chapter 5: Common Multi-State Scenarios for Entrepreneurs

Let’s move from theory to practice. Here are seven common scenarios we see with growing businesses, showing how multi-state tax obligations play out in real situations.

Scenario 1: E-Commerce Business Selling Nationwide

The Situation: You started a Shopify store selling custom home goods from your garage in Bradenton, Florida. Year one, you did $200,000 in sales—mostly to Florida customers, but scattered orders from around the country. Year two, you’re on track for $800,000 in sales, with customers in all 50 states.

Multi-State Tax Implications:

You’ve likely crossed economic nexus thresholds in 15-20 states by now. Here’s what you need to do:

Track sales by state: Review your Shopify data to see where customers are located (shipping address, not billing address)
Identify nexus states: Make a list of every state where you’ve exceeded $100,000 in sales (or their specific threshold)
Register for sales tax: In each nexus state, register for sales tax collection. This needs to happen ASAP—you’re already late in some states.
Update your Shopify settings: Configure sales tax collection for each state. Consider using TaxJar or Avalara to automate this.
Begin collecting tax: Once registered, you must collect sales tax on all future orders to those states.
File returns: Set up a calendar for when each state’s returns are due. Some will be monthly, others quarterly or annual depending on your volume.
Address prior periods: You may need to file voluntary disclosure agreements for past periods where you should have been collecting but weren’t.

Time Investment: Expect 20-40 hours to get registered in all states initially, then 4-8 hours monthly ongoing for filing returns.

Software Solution: TaxJar or Avalara can automate calculations and returns for about $20-$200/month depending on volume.

Professional Help: Many e-commerce businesses handle sales tax themselves with software. However, if you need to address prior non-compliance through VDAs, you should work with a CPA experienced in sales tax.

Scenario 2: Remote Team Distributed Across States

The Situation: Your Florida-based SaaS company has grown to 12 employees. Your team includes:

3 employees in Florida
2 in California
2 in Texas
1 each in Georgia, North Carolina, Virginia, Colorado, and Washington

Multi-State Tax Implications:

You now have employment tax obligations in 9 states, plus potential corporate income tax implications.

Employment Tax Requirements:

Register in each state for income tax withholding (except TX and WA—no income tax)
Register for unemployment insurance in all 9 states
Obtain workers’ compensation in each state
File quarterly wage reports in each state
Withhold and remit state taxes on required schedules

Corporate Income Tax: Because you have employees working remotely, you’ve created physical nexus in each of those states. This means:

You may owe corporate income tax in each state
You’ll need to apportion income among the states
File corporate returns in potentially all 9 states
Understand each state’s apportionment formula

Entity Structure Consideration: If you’re an S-Corp, each of your shareholders may need to file personal income tax returns in each of the 9 states where the company has nexus, reporting their share of the company’s income.

Payroll Software: Use a multi-state payroll service like Gusto, ADP, or Paychex. These services handle most of the state registrations and filings for you (for payroll taxes, not corporate income tax).

Professional Help Needed: Managing corporate income tax across 9 states is complex enough that professional help becomes worth the investment. Expect annual costs of $3,000-$8,000+ for multi-state income tax preparation.

Annual Time Investment (DIY): If handling corporate taxes yourself: 40+ hours annually just for state income tax returns and apportionment calculations.

Scenario 3: SaaS Company Selling Software

The Situation: Your Florida-based SaaS company sells project management software to businesses nationwide. Annual recurring revenue is $2 million. You have no employees outside Florida, no physical presence elsewhere, just digital sales.

Multi-State Tax Implications:

SaaS taxation is one of the murkiest areas of state tax law because:

Is SaaS a product (taxable in most states) or a service (generally not taxable)?
States disagree—some tax SaaS, some don’t, some have unclear rules
The law is evolving as states see potential revenue

States That Tax SaaS (as of 2025):

New York
Pennsylvania
Washington (B&O tax, not sales tax)
Massachusetts
Connecticut
Hawaii
Several others have introduced legislation

States That Don’t Tax SaaS:

Florida
California (unless the software is downloaded)
Most other states, but this is changing

What You Need to Do:

Research current state rules: SaaS taxation changes frequently. What’s not taxable this year might be taxable next year.
Monitor economic nexus: Even for states that don’t tax SaaS currently, track your sales volume—if rules change and you’re already over thresholds, you’ll need to register immediately.
Consider preemptive registration: Some companies register in states that tax SaaS even before hitting economic nexus thresholds, to avoid future back-tax issues.
Track B2B vs B2C: Some states treat business sales differently from consumer sales.
Get exemption certificates: For B2B sales in states that tax SaaS, collect exemption certificates from business customers who are exempt.

Reality Check: Many SaaS companies operate for years without collecting sales tax in states where it’s technically required, simply because the rules are unclear and enforcement is limited. However, this is risky—states are getting more aggressive as they realize SaaS is a growing revenue source.

Professional Guidance: Given the ambiguity, have a CPA experienced in SaaS taxation review your situation and make recommendations on which states to register in proactively.

Scenario 4: Contractor/Consulting Business Working in Multiple States

The Situation: Your Florida-based construction company does projects throughout the Southeast. You regularly work on projects in Georgia, South Carolina, North Carolina, Tennessee, and Alabama. Projects range from 2 weeks to 6 months on-site.

Multi-State Tax Implications:

Physical Nexus: Every project you work on in another state creates physical nexus there. This means potential income tax obligations in each state.

Income Tax Withholding: Some states require withholding on payments to contractors. Your clients may withhold state income tax from your payments.

Temporary vs Permanent Presence: Some states have thresholds (15 days, 30 days, $50,000 in revenue) before nexus is created. However, if you’re regularly working in a state, you likely exceed these thresholds.

What You Need to Do:

Track days and revenue by state: Keep detailed records of where work is performed, how long you’re there, and revenue from each project.
Register for income tax: In states where you’re regularly working, register for corporate income tax and file annual returns.
Apportion income: Calculate what percentage of your income is attributable to each state based on where work was performed.
Handle withholding: If clients withhold state taxes from your payments, you’ll need to report this on your state returns and potentially file for refunds if they overwitheld.
Local business licenses: Many cities/counties require business licenses for contractors working in their jurisdiction, even temporarily.
Sales tax: If you’re selling materials as part of your contracts (not just labor), you may need to collect sales tax in those states.

Professional Help: Multi-state contractor taxation is complex enough that most contractors use a CPA for their state returns. Expect $2,000-$5,000 annually for multi-state tax preparation.

Scenario 5: Amazon FBA Seller

The Situation: You sell private-label products on Amazon. Your inventory is stored in Amazon’s fulfillment centers, which Amazon distributes across the country based on their algorithms. You started in Florida but have no idea where your inventory actually is at any given time.

Multi-State Tax Implications:

Physical Nexus Through Inventory Storage: Inventory sitting in a state creates physical nexus, regardless of how long it’s there or how it got there.

How Amazon Works: Amazon’s system (called IPI – Inventory Performance Index) redistributes inventory to optimize shipping times. Your products could be in 10+ states at any time.

What Amazon Did (The Good News): After Wayfair, Amazon became a marketplace facilitator and began collecting sales tax on behalf of sellers in most states. This means Amazon, not you, is responsible for sales tax collection and remittance on Amazon sales.

What You’re Still Responsible For:

Sales made through your own website or other channels (not through Amazon)
Proper record-keeping
Reporting income correctly
Being available if Amazon or a state audits your account

Where Your Inventory Is: Amazon provides reports showing FBA inventory locations. You should check these regularly to understand your nexus footprint.

Income Tax Obligations: Physical nexus through inventory storage can create corporate income tax obligations in each state where inventory sits, though many small sellers ignore this (risky but common).

Recommendations:

Let Amazon handle sales tax for Amazon sales—don’t try to manage this yourself
Focus on income tax compliance if you’re generating significant profit
If you have your own website, implement sales tax collection through Shopify/TaxJar for those sales
Keep records of where Amazon stores your inventory in case of future audits

Professional Help: Most small FBA sellers (<$1M revenue) handle Amazon sales tax issues on their own since Amazon does the heavy lifting. If you’re also selling direct and generating significant profit, consult with a CPA about income tax obligations.

Scenario 6: Growing Business Opening Second Location

The Situation: Your successful Florida business is opening a satellite office in Kentucky to access talent and expand your market. You’ll have 5 employees in the Kentucky office and maintain your Florida headquarters with 8 employees.

Multi-State Tax Implications:

Everything gets more complex when you have operations in two states:

Immediate Requirements:

Foreign qualification: Register your Florida LLC/corporation to do business in Kentucky (“foreign qualification”)
Kentucky business licenses: Obtain state and local business licenses
Employment tax setup: Register for Kentucky payroll taxes, unemployment insurance, workers’ comp
Corporate income tax: File Kentucky corporate income tax returns
Sales tax: If you’re selling taxable goods/services, register for Kentucky sales tax
Property tax: Real estate or equipment in Kentucky may be subject to property taxes

Apportionment: You’ll now need to apportion income between Florida and Kentucky based on:

Where employees work (payroll factor)
Where property is located (property factor)
Where sales are made (sales factor)

Example:

60% of payroll in Florida, 40% in Kentucky
70% of property in Florida, 30% in Kentucky
Sales to customers in many states (use sales sourcing rules)

Entity Structure Consideration: If you’re an S-Corp, your shareholders will now need to file personal income tax returns in Kentucky reporting their share of Kentucky-source income, even if they live in Florida.

Banking: You’ll likely need Kentucky business bank accounts for operational purposes.

Professional Guidance: Opening a second location in another state should involve consultation with both a CPA and attorney to ensure proper setup. Cost: $2,000-$5,000 for initial setup and guidance, then ongoing annual costs for multi-state tax preparation.

Scenario 7: Trade Show/Event Business

The Situation: Your Florida business attends trade shows and industry events throughout the year. You attend 8-10 shows annually in different states, setting up a booth, selling products directly, and taking orders.

Multi-State Tax Implications:

Temporary Presence: Trade shows create temporary physical presence in a state. Whether this creates nexus depends on:

How many days you’re in the state
How much revenue you generate there
That specific state’s rules
Whether you’re just taking orders vs making sales on-site

Sales Tax Considerations:

If selling products at a trade show, you likely need to collect sales tax in that state
Some states have temporary sales tax permits for trade shows
Some events provide blanket permits covering all vendors
You must research each state’s requirements before attending

Income Tax: Most states have de minimis thresholds for temporary presence (15-30 days annually). If you’re just attending shows, you likely won’t trigger income tax nexus unless you’re there frequently.

What You Need to Do:

Before each show: Research that state’s trade show sales tax requirements
Register for temporary permits if required (many states offer 1-3 day permits)
Collect sales tax on any sales made at the show
File returns for the temporary period
Keep records of all shows attended (dates, locations, revenue)
Track cumulative days in each state throughout the year

Reality Check: Many trade show vendors don’t properly handle sales tax at shows, assuming it’s too temporary to matter. This is technically non-compliant but enforcement is limited unless you’re a regular exhibitor.

Recommendation: For major shows where you generate significant revenue, register and collect sales tax properly. For smaller shows, assess the risk vs administrative burden.

The Common Thread: Notice how in every scenario, what starts as a simple business decision (selling online, hiring remotely, attending a show) creates cascading tax obligations? This is the reality of growing a business in today’s multi-state economy. The obligations exist whether you know about them or not—and ignorance isn’t a defense in a tax audit.

Chapter 6: Technology and Systems for Multi-State Compliance

You can’t manage multi-state tax compliance with spreadsheets and good intentions. The volume of filings, the complexity of calculations, and the risk of errors make technology essential once you cross into even a few states.

Manual vs Automated Solutions

When Manual Works (Rarely):

Single state beyond Florida (maybe)
Very low transaction volume
Simple product/service with clear tax treatment
You’re a tax professional yourself

When Manual Fails:

Multiple states (3+)
High transaction volume
Complex product mix
Changing nexus footprint
Limited time to devote to tax compliance

The truth is, most growing businesses move to automated solutions once they hit 3-5 states with nexus. The time savings and error reduction justify the cost.

Software Solutions Overview

Sales Tax Automation

Avalara: Industry leader, robust features

Pricing: Starts around $200/month, scales with volume
Features: Automatic rate updates, exemption certificate management, multi-channel integration, return filing services
Best for: High-volume sellers, complex product catalogs
Integrations: Shopify, WooCommerce, Amazon, QuickBooks, NetSuite, most major platforms

TaxJar: Popular with smaller businesses

Pricing: $19/month for reports only, $99/month for full features
Features: Economic nexus analysis, automated calculations, return filing assistance
Best for: Small to mid-size e-commerce businesses
Integrations: Shopify, Amazon, eBay, Etsy, WooCommerce, Magento

TaxCloud: Free basic service

Pricing: Free for calculations, paid services for returns
Features: Real-time tax calculation, exemption management
Best for: Businesses wanting to minimize costs
Limitations: Less robust than paid alternatives, self-service returns

Vertex: Enterprise-level solution

Pricing: Custom (typically $5,000+ annually)
Features: Comprehensive tax determination, indirect tax management, audit defense
Best for: Large businesses, complex needs
Integrations: Enterprise ERP systems

Multi-State Payroll

Gusto: Best for small businesses

Pricing: $40/month base + $6 per person
Features: Multi-state payroll, tax filing, W-2s, direct deposit, benefits administration
Handles: All state registrations, filings, payments automatically
Best for: Businesses with 1-50 employees

ADP: Comprehensive payroll provider

Pricing: Custom quotes, generally higher than Gusto
Features: Full-service payroll, HR tools, benefits, compliance
Best for: Established businesses wanting full-service support

Paychex: Mid-market solution

Pricing: Custom quotes
Features: Payroll, HR, benefits, retirement plans
Best for: Growing businesses needing scalable solutions

QuickBooks Payroll: Integration with accounting

Pricing: $45/month + $5 per employee
Features: Payroll, tax filing, QuickBooks integration
Best for: Businesses already using QuickBooks for accounting

Accounting Software Integration

QuickBooks Online: Most popular

Multi-state tax tracking capabilities
Integration with sales tax automation tools
Payroll options available
Limitation: Not designed specifically for multi-state apportionment

Xero: Alternative to QBO

Clean interface, good integrations
Multi-currency support
Sales tax tracking
Similar limitations to QBO for complex multi-state scenarios

NetSuite: Enterprise solution

Built-in multi-state tax capabilities
Advanced apportionment features
Pricing: $10,000-$100,000+ annually
Best for: Larger businesses with complex needs

Data You Need to Track

Regardless of what software you use, you need to maintain certain data:

Customer/Transaction Data:

Customer shipping address (for sales tax sourcing)
Customer billing address
Transaction date and amount
Product/service sold
Tax collected
Exemption certificates (for wholesale/resale customers)

Employee Data:

Employee home address (for payroll tax)
Work location (for income tax apportionment)
Hire date and termination date
Wages and withholding by state
Days worked in each state (for mobile employees)

Business Operations Data:

Where inventory is stored (quantity and value by location)
Property and equipment locations
Office locations
Days and revenue by state (for contractors/consultants)

Compliance Tracking:

State registration numbers and dates
Filing deadlines by state and frequency
Payment dates and amounts
Correspondence with state tax departments

What Technology Can’t Replace

Even with the best software, technology can’t handle:

Strategic Decisions:

What entity structure is best for your multi-state operations?
Should you restructure to minimize tax exposure?
When should you register in a state proactively vs waiting?
How should you handle prior period non-compliance?

Interpretation of Ambiguous Rules:

Is your SaaS product taxable in a specific state?
Does attending a trade show create nexus?
How should you source a particular type of service revenue?
What constitutes “reasonable compensation” for S-Corp owners in multiple states?

State Tax Notices and Audits:

How to respond to a state nexus questionnaire?
Defending positions in an audit
Negotiating voluntary disclosure agreements
Appealing assessments

Multi-State Planning:

Structuring business expansion to minimize tax
Choosing where to locate facilities or hire employees
Planning for business sale or acquisition
Evaluating the tax impact of new service offerings

Software Limitations:

Sales tax software handles transaction taxes well, but doesn’t touch income tax
Payroll software handles withholding, but not corporate income tax implications
Accounting software can track data, but not complex apportionment calculations
None of it provides strategic tax planning

The Right Balance: Think of software as handling the repetitive, rule-based tasks (calculating rates, filing returns, tracking deadlines), while professional guidance handles the judgment calls, strategic decisions, and complex situations.

Transition to Services: The right technology makes compliance possible. The right CPA makes it strategic.

Chapter 7: Risk Management and Red Flags

Understanding your obligations is one thing. Understanding what happens when you get it wrong—and how to minimize that risk—is equally important.

Common Mistakes That Trigger State Audits

State tax departments aren’t auditing random businesses. They’re using data and analytics to find non-compliant taxpayers. Here are the red flags that trigger attention:

Waiting Too Long to Register

The most common mistake: You cross economic nexus thresholds but don’t register immediately. You think “I’ll get to it eventually” or “They won’t notice.”

States notice. They’re comparing:

Credit card transaction data (states share data)
Amazon and marketplace facilitator reports
Prior year tax returns showing multi-state operations
Public business listings and registrations
Social media and advertising showing operations in their state

When you finally register two years late, you’re immediately flagged for an audit to assess back taxes.

Inconsistent Filing

You register for sales tax, file for a few months, then stop filing because you’re busy or sales dropped. This creates an immediate red flag. States assume you’re still making sales but not reporting them.

If you’re registered, you must file every required period even if it’s a zero-dollar return.

Claiming Exemptions Incorrectly

Exemption certificates (for resale, wholesale, non-profit purchases) are the most audited aspect of sales tax. States review whether:

You have valid certificates on file
The certificates are complete and signed
The exemption actually applies to the transaction
You’re selling to legitimate wholesalers (not consumers claiming exemption)

Missing exemption certificates can result in you owing tax on those “exempt” sales plus penalties.

Not Tracking Economic Nexus Thresholds

You cross the $100,000 sales threshold in March but don’t register until December. The state can assess tax for the full year, plus penalties for late registration.

You need systems to monitor your sales by state in real-time, not annually when doing taxes.

Ignoring Letters from State Tax Departments

States send nexus questionnaires, information requests, and “friendly” letters asking if you should be registered. Ignoring these doesn’t make them go away—it makes the eventual assessment larger and less negotiable.

State Tax Department Enforcement

How States Find Non-Compliant Businesses

States are increasingly sophisticated in identifying businesses with nexus:

Data Sharing Between States: The Streamlined Sales Tax Governing Board facilitates data sharing among states. If you register in one state, others may learn about your multi-state operations.
Marketplace Data: States get data from Amazon, eBay, Etsy, and other platforms showing seller activity by state.
Third-Party Data Services: States purchase data from credit card processors, shipping companies, and data analytics firms.
Public Information: Your website, LinkedIn, job postings, and business registrations in other states are all public information.
Cross-Audits: If one state audits you, they share findings with other states.
Whistleblowers: Competitors, former employees, or customers can report businesses they believe aren’t complying.

The “Wayfair Effect”

Since the Wayfair decision, states have been aggressive about enforcing economic nexus rules. They see this as new revenue that doesn’t require new taxes—just enforcing collection from businesses already making sales in their state.

States are:

Sending tens of thousands of nexus questionnaires
Conducting more audits
Participating in multi-state audit programs
Increasing penalties for non-compliance

Penalties and Interest

Late Registration Penalties

If you register late (after you had nexus), states can:

Assess back taxes for all periods you should have been registered
Apply late filing penalties (typically 5-25% of tax due)
Apply late payment penalties
Charge interest on unpaid taxes

Total penalties can easily reach 40-50% of the base tax due.

Late Filing Penalties

Even if you don’t owe tax (zero sales), failing to file returns results in penalties:

Fixed dollar amount per period (e.g., $50-$200 per missed return)
Percentage of tax due if you do owe tax
Accumulates monthly, so a year of missed returns means 12x the penalty

Failure to Pay Penalties

If you file but don’t pay:

Typically 0.5-1% per month
Can reach 25% of tax due
Separate from late filing penalty (they stack)

Interest Compounds Quickly

Interest rates vary by state but typically range from 3-10% annually, compounding monthly. A $10,000 tax bill from three years ago could have $3,000+ in interest alone.

Personal Liability

In many states, business owners can be personally liable for unpaid sales tax. Even if your business is an LLC or corporation, states can “pierce the veil” and come after your personal assets for unpaid sales tax.

This is especially true if the state believes you:

Collected tax from customers but didn’t remit it to the state
Willfully disregarded tax obligations
Closed the business to avoid paying taxes

Voluntary Disclosure Agreements

What They Are

A Voluntary Disclosure Agreement (VDA) is a formal program most states offer where you:

Proactively admit you haven’t been complying
Agree to register and begin complying going forward
Negotiate reduced liability for past periods

Benefits of VDAs:

Reduced look-back period (typically 3-4 years instead of 6-10 years or no statute of limitations)
Waived or reduced penalties
Sometimes reduced or waived interest
Anonymity during negotiation (you work through a representative)
Legal closure—states agree not to assess more tax for disclosed periods

When to Consider a VDA

VDAs are appropriate when:

You’ve been operating in a state for years without registering
You have significant back-tax exposure ($10,000+)
You want to become compliant but fear the cost of full back-tax liability
You’re about to be noticed by the state (better to come forward first)

How VDAs Work

Engage a representative (CPA or attorney specializing in VDAs)
Initial contact with the state is made anonymously
Estimate tax liability for the VDA look-back period
Negotiate terms with the state
Execute agreement once terms are acceptable
Pay agreed amount and register for ongoing compliance
Receive closure from the state for past periods

Costs

VDA representation typically costs:

Professional fees: $2,000-$10,000+ depending on complexity
Back taxes owed for look-back period
Some penalties/interest (reduced from full liability)

Important: VDAs should be handled by professionals. DIY approaches often backfire because you lose anonymity and negotiating leverage once you’ve identified yourself to the state.

Audit Defense

What to Do When You Get a State Notice

States send various types of notices:

Nexus Questionnaires: Asking if you have nexus. These aren’t audits but can lead to them. Consider getting professional help before responding.
Information Document Requests (IDRs): Requesting specific records. You’re legally required to respond within the timeframe given.
Notice of Proposed Assessment: Claiming you owe tax. This is serious—respond quickly with documentation or professional representation.
Audit Notices: Formal audit of your business. You need professional help for this.

Documentation Requirements

In an audit, states will request:

Complete transaction records (all sales, all purchases)
Exemption certificates
Bank statements
General ledgers
Inventory records
Employee records and locations
Proof of where services were performed

The burden of proof is on you to show you either:

Didn’t have nexus
Properly collected and remitted tax
Sales were actually exempt

Audit Timelines

State audits typically take:

3-6 months for simple audits
6-12 months for complex audits
12-24 months for multi-state audits

During this time, you’ll be responding to information requests, meeting with auditors, and potentially negotiating findings.

Working with State Auditors

Best practices:

Be professional and cooperative
Provide requested information promptly
Don’t volunteer information beyond what’s requested
Question findings you disagree with
Consider having your CPA or attorney present during meetings
Document all interactions

When to Appeal

If you disagree with audit findings, most states have formal appeal processes:

Informal conference with audit supervisor
Formal administrative appeal
Tax court litigation (last resort)

Appeals are often successful when you have good documentation and reasonable arguments. However, they extend the timeline and often require attorney involvement.

Proactive vs Reactive Compliance

Cost of Doing It Right from the Start

Let’s compare two scenarios:

Proactive Approach:

Monitor nexus quarterly: Minimal time
Register when thresholds are crossed: $0-$500 per state
Use sales tax automation software: $100-$500/month
Annual CPA review: $1,000-$3,000
Ongoing compliance: Part of normal operations

Total annual cost: $5,000-$10,000 for a growing multi-state business

Reactive Approach (After Getting Caught):

Nexus questionnaire triggers investigation
Back taxes for 3 years: $50,000 (example)
Penalties and interest: $20,000
VDA professional fees: $5,000
Audit defense: $10,000
Stress, time, and opportunity cost: Incalculable

Total cost: $85,000+ (plus ongoing compliance costs you should have been paying anyway)

The Multiplication Factor: These costs multiply by the number of states involved. Get caught in 10 states instead of 1, and reactive costs balloon to $500,000+.

Cost of Fixing It Later

Beyond the financial costs, there are other impacts:

Reputational Considerations:

Tax liens become public record
Damage to business credit
Concerns from investors, lenders, or potential acquirers
Loss of business licenses or good standing status

Impact on Business Valuation/Sale: If you’re planning to sell your business:

Buyers will uncover tax non-compliance in due diligence
Undisclosed tax liabilities reduce sale price dollar-for-dollar (or kill the deal)
You may need to establish escrow accounts to cover potential liabilities
Sale may be delayed while you clean up compliance issues

Growth Constraints:

Can’t expand to states where you’re non-compliant
May lose marketplace seller accounts (Amazon, eBay) if they discover non-compliance
Payment processors may freeze accounts
Difficulty obtaining financing

The Bottom Line: Proactive compliance is always cheaper than reactive remediation. Always.

Chapter 8: When to Get Professional Help

If you’ve read this far, you understand that multi-state tax compliance is complex. The question isn’t whether it’s complicated—it clearly is. The question is: at what point does the complexity justify professional help?

The DIY Breaking Point

Signs You’ve Outgrown Self-Managed Compliance:

You’re spending more time on tax compliance than growing your business: If you’re spending 10+ hours monthly on multi-state tax filing, that’s time not spent on marketing, product development, or customer service.
You’re losing sleep over whether you’re doing it right: Anxiety about potential audits or mistakes is a sign the risk has exceeded your comfort level.
You’ve received notices from states: Once states start contacting you, the complexity has increased beyond typical DIY capabilities.
You have nexus in 5+ states: Managing compliance in a few states is possible for detail-oriented business owners. Beyond five, the administrative burden becomes overwhelming.
Your entity structure is complex: If you have multiple entities, partnerships, S-Corp with multiple shareholders, or C-Corp, professional help becomes valuable.
You’re making strategic business decisions with tax implications: Hiring in a new state, opening a new location, restructuring ownership—these decisions should involve tax planning.
You’re not confident in your apportionment calculations: If you’re guessing at how to divide income among states, you’re either overpaying (bad for you) or underpaying (bad when audited).

Time Cost vs Dollar Cost

Let’s do some math:

DIY Approach:

Learning multi-state tax rules: 20 hours initially
Monthly sales tax returns (5 states): 8 hours
Quarterly payroll tax filings (3 states): 6 hours
Annual income tax returns (5 states): 40 hours
Research and staying current: 10 hours annually

Total annual time: 200+ hours

At an opportunity cost of $100/hour (what you could earn working on your business), that’s $20,000+ in lost opportunity, not counting the risk of errors.

Professional Approach:

Sales tax software + filing service: $3,000 annually
Multi-state payroll service: $2,500 annually
CPA for income tax returns: $5,000 annually
Quarterly advisory calls: $2,000 annually

Total annual cost: $12,500

Savings: $7,500 + peace of mind + correct compliance

Risk Exposure Calculation

Beyond time, consider the risk:

DIY Risks:

Errors in apportionment calculations: Could cost thousands in over/underpayment
Missed filing deadlines: Penalties of 5-25% per state
Improper nexus determinations: Failure to register where required
No audit defense expertise: Higher settlements in audits

Professional Risk Mitigation:

Errors are covered by professional liability insurance
Deadlines managed systematically
Nexus monitoring as part of service
Audit defense included or available

The question isn’t whether you can DIY multi-state taxes (you probably can, with enough time and research). The question is whether you should, given the opportunity cost and risk.

What to Look for in Multi-State Tax Support

Not all CPAs handle multi-state taxation. It’s a specialized area that requires:

Experience Across Multiple States

Look for a firm that:

Regularly files returns in 10+ states
Understands variations in state tax law
Has relationships with state tax departments
Can navigate different state requirements

Ask: “How many states do you typically handle for clients? Can you share examples of multi-state situations similar to mine?”

Technology-Forward Approach

Modern multi-state tax support should include:

Integration with your accounting software
Sales tax automation recommendations and setup
Cloud-based document sharing
Efficient processes that don’t require mailing paper documents

Ask: “What technology do you use for multi-state tax management? How will we share documents and communicate?”

Proactive vs Reactive Service

You want a CPA who:

Monitors your nexus status regularly
Alerts you before you cross thresholds
Provides strategic planning for growth
Anticipates issues before they become problems
Offers quarterly check-ins, not just annual tax filing

Ask: “How often will we communicate? Will you proactively monitor my nexus status or only address it when I ask?”

Strategic Planning vs Just Compliance

The best multi-state tax support goes beyond compliance:

Entity structure optimization
State selection for expansion
Tax impact analysis for major decisions
Multi-state tax planning strategies
Guidance on minimizing overall tax burden

Ask: “Can you help me plan strategically to minimize my multi-state tax burden, or do you only prepare returns?”

Clear Communication

Multi-state tax is complex, but explanations shouldn’t be. Look for:

Ability to explain concepts in plain English
Patience with questions
Educational approach (teaching you along the way)
Transparency about costs and what’s included

Ask: “How do you handle billing? What’s included in your service and what would be additional?”

How Milbrod & Hessel Approaches Multi-State Taxation

At Milbrod & Hessel, we’ve built our practice around supporting growing businesses that face multi-state tax complexity. Here’s our approach:

Comprehensive Multi-State Expertise

We regularly handle tax compliance for clients operating in 20+ states. Our team stays current on:

Economic nexus thresholds and changes
State-specific apportionment rules
Industry-specific tax treatment
Emerging issues (like remote work tax implications)

Florida and Kentucky Presence

With offices in Florida and Kentucky, we understand the unique considerations of businesses operating in both states. We can guide you through the specific requirements of both states based on firsthand experience.

Technology-Integrated Service

We work with:

Cloud-based accounting systems (QBO, Xero, NetSuite)
Sales tax automation platforms (Avalara, TaxJar)
Multi-state payroll providers (Gusto, ADP)
Secure document sharing and communication tools

Our goal is to make multi-state compliance as efficient as possible through technology, while providing the strategic guidance technology can’t replace.

Proactive Nexus Monitoring

For our multi-state clients, we:

Quarterly reviews of where you’re doing business
Monitoring of sales thresholds by state
Alerts when registration becomes necessary
Annual comprehensive multi-state planning sessions

You shouldn’t have to worry about whether you’re crossing nexus thresholds—we track this for you.

Strategic Entity Structure Planning

Before you expand to a new state or restructure your business, we analyze:

Tax impact of different entity structures
Optimal states for placing certain operations
How to minimize overall tax burden
Long-term implications of structural decisions

Many tax problems are easier to prevent than fix. Strategic planning at decision points is critical.

Award-Winning Service

Milbrod & Hessel has been recognized by the Herald-Tribune as:

Best Tax Preparer: 2022, 2023, 2024
Best Accounting Firm: 2023, 2024

These awards reflect our commitment to delivering exceptional service and building strong client relationships.

Established in 2000

With over 25 years of experience, we’ve seen businesses grow from Florida-only operations to multi-state and even international enterprises. We understand the journey and can guide you through each stage.

Getting Started

If you’re facing multi-state tax complexity, here’s how we can help:

Multi-State Compliance Assessment

We start with a comprehensive review of:

Where you’re currently doing business
What tax obligations you likely have
What you’re doing correctly
What needs attention
What your ongoing compliance needs will be

Gap Analysis

We identify:

States where you should be registered but aren’t
Filing requirements you’re missing
Prior period exposure
Risk areas that need immediate attention

Remediation Plan

If you have prior non-compliance, we develop a plan:

Which states to address first (highest risk/exposure)
Whether VDAs are appropriate
How to minimize penalties and interest
Timeline for getting fully compliant

Ongoing Management

Once you’re compliant, we provide:

All state tax return preparation and filing
Nexus monitoring and registration management
Payroll tax coordination (if needed)
Strategic tax planning
Response to state notices and audit defense

Strategic Tax Planning

Beyond compliance, we help you:

Structure expansions to minimize tax impact
Choose optimal locations for operations
Make entity structure decisions with tax in mind
Plan for ownership changes or business sales
Minimize your overall multi-state tax burden

Clear CTA: Ready to discuss your multi-state tax situation? Schedule a consultation with us to review your specific needs and how we can help. We’ll provide an honest assessment of what you need, what you can manage yourself, and where professional support makes sense.

Schedule Your Multi-State Tax Consultation

Conclusion

Multi-state taxation is one of the most complex areas of small business tax compliance. What seems simple on the surface—selling products in other states, hiring remote employees, or attending a trade show—creates cascading obligations across multiple jurisdictions.

Key Takeaways

Multi-State Taxation Is More Complex Than Most Entrepreneurs Realize: It’s not just about filing in multiple states—it’s about understanding different rules, calculation methods, and compliance requirements in each jurisdiction.
The 2018 Wayfair Decision Changed Everything: Economic nexus means even small businesses can have obligations in 20+ states based solely on sales volume. There’s no hiding behind physical presence anymore.
Each State Has Its Own Rules: There is no universal “multi-state tax law.” Every state has different thresholds, rates, apportionment formulas, filing frequencies, and requirements. What works in one state may be completely wrong in another.
DIY Is Possible for Simple Situations: If you have nexus in just a couple states, low complexity, and time to learn, you might handle it yourself with the help of good software.
But DIY Becomes Risky As You Grow: Once you cross into 5+ states, have employees in multiple locations, or face complex apportionment situations, professional help typically pays for itself through time savings and error avoidance.
Technology Helps, But Doesn’t Replace Strategic Guidance: Sales tax software handles calculations. Payroll software handles withholding. But neither handles strategic decisions about entity structure, expansion planning, or complex nexus questions.
Proactive Compliance Is Always Cheaper Than Reactive Remediation: Getting it right from the start costs a fraction of what it costs to fix years of non-compliance. The penalties, interest, and professional fees for catching up are always higher than the cost of staying current.

The Path Forward

If you’re reading this guide, you’re likely in one of three situations:

You’re Worried You Might Have Obligations You’re Not Meeting: Conduct an honest assessment of where you’re doing business, then address any gaps. If you have significant exposure, consider voluntary disclosure. The longer you wait, the more expensive it becomes.

You’re Currently Managing Multi-State Compliance and It’s Overwhelming: This is common. Evaluate whether the time and stress are worth the cost savings of DIY. Often, they’re not. Outsourcing to professionals and technology can free you to focus on what you do best.

You’re Planning to Expand and Want to Do It Right: This is the best position to be in. Proactive planning before you create nexus allows you to make strategic decisions about where and how to expand. Engage a CPA with multi-state experience before you make major moves.

Final Thought

Growing beyond Florida is exciting. Your business is succeeding, you’re reaching new markets, you’re building a team. Multi-state tax compliance doesn’t have to be scary if you have the right guidance.

The key is to:

Understand what your obligations actually are
Put systems in place to track them
Get help when complexity exceeds your capacity
Stay proactive rather than reactive
Make strategic decisions with tax implications in mind

You didn’t start your business to become a multi-state tax expert. But you did start it to build something successful—and protecting that success means ensuring you’re compliant as you grow.

Ready to Get Started?

Whether you need a comprehensive compliance assessment, help with current filings, or strategic planning for expansion, Milbrod & Hessel can help. We’ve guided hundreds of Florida businesses through the complexities of multi-state taxation.

Schedule a consultation today to discuss your specific situation. We’ll provide an honest assessment of what you need and how we can help.

Because growing your business should be exciting—not overwhelming.

Appendix A: Economic Nexus Threshold Quick Reference

Note: These thresholds change periodically. Verify current requirements with each state’s department of revenue.

State	Sales Threshold	Transaction Threshold	Effective Date
Alabama	$250,000	None	10/1/2018
Alaska	No state sales tax	N/A	N/A
Arizona	$100,000	None	10/1/2019
Arkansas	$100,000	200	7/1/2019
California	$500,000	None	4/1/2019
Colorado	$100,000	None	12/1/2018
Connecticut	$100,000	200	12/1/2018
Delaware	No state sales tax	N/A	N/A
Florida	$100,000	None	7/1/2021
Georgia	$100,000	200	1/1/2019
Hawaii	$100,000	200	7/1/2018
Idaho	$100,000	None	6/1/2019
Illinois	$100,000	200	10/1/2018
Indiana	$100,000	200	10/1/2018
Iowa	$100,000	None	1/1/2019
Kansas	$100,000	None	10/1/2019
Kentucky	$100,000	200	10/1/2018
Louisiana	$100,000	200	7/1/2020
Maine	$100,000	None	7/1/2018
Maryland	$100,000	200	10/1/2018
Massachusetts	$100,000	None	10/1/2019
Michigan	$100,000	200	10/1/2018
Minnesota	$100,000	200	10/1/2018
Mississippi	$250,000	None	9/1/2018
Missouri	$100,000	None	1/1/2023
Montana	No state sales tax	N/A	N/A
Nebraska	$100,000	200	1/1/2019
Nevada	$100,000	200	10/1/2018
New Hampshire	No state sales tax	N/A	N/A
New Jersey	$100,000	200	11/1/2018
New Mexico	$100,000	None	7/1/2019
New York	$500,000	100	6/21/2018
North Carolina	$100,000	200	11/1/2018
North Dakota	$100,000	None	10/1/2018
Ohio	$100,000	200	8/1/2019
Oklahoma	$100,000	None	11/1/2019
Oregon	No state sales tax	N/A	N/A
Pennsylvania	$100,000	None	7/1/2019
Rhode Island	$100,000	200	7/1/2019
South Carolina	$100,000	None	11/1/2018
South Dakota	$100,000	200	11/1/2018
Tennessee	$100,000	None	10/1/2019
Texas	$500,000	None	10/1/2019
Utah	$100,000	200	1/1/2019
Vermont	$100,000	200	7/1/2018
Virginia	$100,000	200	7/1/2019
Washington	$100,000	None	10/1/2018
West Virginia	$100,000	200	1/1/2019
Wisconsin	$100,000	None	10/1/2018
Wyoming	$100,000	200	2/1/2019

Appendix B: State Income Tax Quick Reference

State	Corporate Income Tax	Top Rate	Apportionment Formula	Notes
Alabama	Yes	6.5%	3-factor (equal weighted)	Local taxes may apply
Alaska	Yes	9.4%	3-factor (double-weighted sales)	No personal income tax
Arizona	Yes	4.9%	Single sales factor
Arkansas	Yes	5.3%	Single sales factor
California	Yes	8.84%	Single sales factor	High rates, aggressive enforcement
Colorado	Yes	4.55%	Single sales factor	Flat rate
Connecticut	Yes	7.5%	Single sales factor
Delaware	Yes	8.7%	3-factor (equal weighted)	No sales tax
Florida	No	N/A	N/A	No corporate or personal income tax
Georgia	Yes	5.75%	Single sales factor
Hawaii	Yes	6.4%	3-factor (equal weighted)
Idaho	Yes	5.8%	Single sales factor
Illinois	Yes	9.5%	Single sales factor	Includes personal property replacement tax
Indiana	Yes	4.9%	Single sales factor	Flat rate
Iowa	Yes	5.5%	Single sales factor	Rate reduced from 12% over time
Kansas	Yes	4.0%	3-factor (equal weighted)	Plus surtax on higher income
Kentucky	Yes	5.0%	Single sales factor
Louisiana	Yes	7.5%	Single sales factor
Maine	Yes	8.93%	Single sales factor
Maryland	Yes	8.25%	3-factor (double-weighted sales)
Massachusetts	Yes	8.0%	Single sales factor
Michigan	Yes	6.0%	Single sales factor
Minnesota	Yes	9.8%	Single sales factor
Mississippi	Yes	5.0%	3-factor (equal weighted)
Missouri	Yes	4.0%	3-factor (equal weighted)
Montana	Yes	6.75%	3-factor (equal weighted)	No sales tax
Nebraska	Yes	5.84%	Single sales factor
Nevada	No	N/A	N/A	Commerce tax applies instead
New Hampshire	Yes	7.5%	3-factor (double-weighted sales)	No personal income tax; business profits tax
New Jersey	Yes	9.0%	Single sales factor	High rates
New Mexico	Yes	5.9%	3-factor (equal weighted)
New York	Yes	6.5%	Single sales factor	Plus NYC unincorporated business tax
North Carolina	Yes	2.5%	Single sales factor	Low flat rate
North Dakota	Yes	4.31%	3-factor (equal weighted)
Ohio	No	N/A	N/A	Commercial Activity Tax (gross receipts) instead
Oklahoma	Yes	4.0%	3-factor (equal weighted)
Oregon	Yes	7.6%	Single sales factor	No sales tax
Pennsylvania	Yes	8.99%	Single sales factor	High flat rate
Rhode Island	Yes	7.0%	Single sales factor
South Carolina	Yes	5.0%	Single sales factor
South Dakota	No	N/A	N/A	No income tax
Tennessee	Yes	6.5%	3-factor (double-weighted sales)	Franchise tax also applies; no personal income tax
Texas	No	N/A	N/A	Franchise tax (gross receipts) instead
Utah	Yes	4.85%	Single sales factor
Vermont	Yes	8.5%	3-factor (double-weighted sales)
Virginia	Yes	6.0%	Single sales factor
Washington	No	N/A	N/A	B&O tax (gross receipts) instead; no income tax
West Virginia	Yes	6.5%	3-factor (equal weighted)
Wisconsin	Yes	7.9%	Single sales factor
Wyoming	No	N/A	N/A	No income tax

Appendix C: Multi-State Compliance Checklist

Use this checklist to assess your current compliance status:

Sales Tax Compliance

☐ I track my sales by customer location (shipping address) for all sales channels

☐ I know the economic nexus thresholds for all states where I have customers

☐ I have registered for sales tax in every state where I’ve exceeded the threshold

☐ I collect sales tax on all taxable sales in states where I’m registered

☐ I file sales tax returns on time in every state (even zero-dollar returns)

☐ I maintain exemption certificates for all wholesale/exempt sales

☐ I use sales tax automation software or manually calculate rates correctly

☐ I reconcile sales tax collected with sales tax remitted quarterly

☐ I have systems to monitor when I cross new state thresholds

Income Tax Compliance

☐ I understand which states I have income tax nexus in

☐ I file corporate income tax returns in every state where I have nexus

☐ I use appropriate apportionment formulas for each state

☐ I maintain documentation supporting my apportionment calculations

☐ If I’m an S-Corp owner, I file personal returns in states with nexus

☐ I pay estimated taxes in states that require them

☐ I reconcile my federal return with state returns (income should tie out)

Employment Tax Compliance

☐ I’m registered for payroll taxes in every state where I have employees

☐ I withhold state income tax for each employee based on their work location

☐ I remit withheld taxes on the required schedule for each state

☐ I file quarterly wage reports in every state where I have employees

☐ I pay unemployment insurance (SUTA) in every relevant state

☐ I have workers’ compensation coverage for employees in each state

☐ I provide W-2s with proper state withholding information

Record Keeping

☐ I maintain records of where all inventory is stored by state

☐ I track employee locations and days worked in each state (for mobile employees)

☐ I keep exemption certificates organized and readily accessible

☐ I document where services are performed for apportionment purposes

☐ I maintain correspondence from all state tax departments

☐ I keep records of all state registrations and account numbers

Proactive Monitoring

☐ I review nexus status quarterly as the business grows

☐ I stay informed about changing state tax laws

☐ I consult with a CPA before making major business decisions with tax implications

☐ I have a plan for addressing any prior period non-compliance

☐ I budget appropriately for multi-state tax obligations

Risk Assessment

☐ I’ve assessed my exposure in states where I may have had nexus but wasn’t registered

☐ I understand the potential cost of voluntary disclosure if needed

☐ I have professional representation available if I receive audit notices

☐ I review my compliance annually with a multi-state tax specialist

Scoring:

30-35 checked: Strong compliance position
20-29 checked: Some gaps to address
10-19 checked: Significant compliance issues
0-9 checked: High risk; seek professional help immediately

Appendix D: Glossary of Multi-State Tax Terms

Apportionment: The method of dividing a business’s income among the states where it operates to determine how much each state can tax. Typically uses factors like property, payroll, and sales.

Economic Nexus: A connection with a state based on sales volume or transaction count, without physical presence. Created by the Wayfair Supreme Court decision.

Exemption Certificate: A form provided by a buyer claiming their purchase is exempt from sales tax (typically for resale or wholesale purchases). Sellers must keep these on file.

Factor: A component used in apportionment formulas (property factor, payroll factor, or sales factor) to determine what percentage of income is taxable in each state.

Filing Frequency: How often you must file tax returns in a state (monthly, quarterly, or annually), typically based on your tax liability volume.

Foreign Qualification: The process of registering a business entity formed in one state to do business in another state. Required when you have physical operations in a new state.

Marketplace Facilitator: A platform like Amazon, eBay, or Etsy that facilitates sales between sellers and buyers. In most states, marketplace facilitators are responsible for collecting and remitting sales tax on behalf of sellers.

Nexus: The connection between a business and a state that creates a tax obligation. Can be physical (presence in the state) or economic (sales volume to the state).

Physical Nexus: Connection with a state through physical presence, such as offices, employees, inventory, or property. Creates both sales tax and income tax obligations.

Sales Factor: In apportionment, the percentage of a company’s total sales that are made to customers in a particular state.

Sourcing: The rules for determining where a sale occurs for tax purposes. Can be based on where the seller ships from, where the customer receives the product, or where the benefit is received.

SUTA: State Unemployment Tax Act. The state unemployment insurance tax employers must pay based on employee wages.

Threshold: The level of sales or transactions that triggers a requirement to register and collect tax in a state (e.g., $100,000 in sales or 200 transactions).

VDA (Voluntary Disclosure Agreement): A formal agreement with a state where a business voluntarily discloses past non-compliance in exchange for reduced penalties and limited look-back periods.

Wayfair Decision: The 2018 U.S. Supreme Court case (South Dakota v. Wayfair) that ruled states can require out-of-state businesses to collect sales tax based on economic activity alone, without physical presence.

Withholding: The practice of deducting state income tax from employee paychecks and remitting it to the state on behalf of the employee.

Appendix E: Useful Resources

State Tax Department Links

Major States for Florida Businesses:

Florida Department of Revenue: floridarevenue.com
Georgia Department of Revenue: dor.georgia.gov
North Carolina Department of Revenue: ncdor.gov
Texas Comptroller: comptroller.texas.gov
California Franchise Tax Board: ftb.ca.gov
Kentucky Department of Revenue: revenue.ky.gov

Multi-State Resources:

Federation of Tax Administrators: taxadmin.org (links to all state tax departments)
Streamlined Sales Tax: streamlinedsalestax.org (nexus information)

Industry Organizations

American Institute of CPAs (AICPA): aicpa.org
National Association of Tax Professionals: natptax.com
Council on State Taxation: cost.org

Software Providers

Sales Tax Automation:

Avalara: avalara.com
TaxJar: taxjar.com
Vertex: vertexinc.com
TaxCloud: taxcloud.com

Payroll Services:

Gusto: gusto.com
ADP: adp.com
Paychex: paychex.com
QuickBooks Payroll: quickbooks.intuit.com/payroll

Accounting Software:

QuickBooks Online: quickbooks.intuit.com
Xero: xero.com
NetSuite: netsuite.com

Professional Associations

National Society of Accountants: nsacct.org
Institute for Professionals in Taxation: ipt.org
State CPA Societies (Florida Institute of CPAs: ficpa.org)

Educational Resources

IRS Small Business Resources: irs.gov/businesses/small-businesses-self-employed
Small Business Administration: sba.gov
SCORE (Free business mentoring): score.org

Document Information:

Guide created: December 2025
Prepared by: Milbrod & Hessel CPA, LLC
Contact: kara@heroic.cpa | 866-333-4376
Website: milbrodhessel.cpa

Disclaimer: This guide provides general information about multi-state tax compliance and should not be considered legal or tax advice for your specific situation. State tax laws change frequently, and individual circumstances vary. Consult with a qualified tax professional before making decisions based on this information.

Ready to Discuss Your Multi-State Tax Situation?

Schedule a consultation with Milbrod & Hessel to get personalized guidance for your business.

Introduction

Chapter 1: Understanding Nexus – When Do You Owe Taxes in Another State?

What Is Nexus?

Types of Nexus

Common Nexus Triggers Florida Businesses Miss

Chapter 2: Sales Tax Compliance Across State Lines

When Florida Businesses Must Collect Sales Tax Elsewhere

What You’re Actually Selling Matters

Marketplace Facilitator Rules

The Registration Process

Ongoing Compliance

Chapter 3: Income Tax – When Your Florida Advantage Disappears

Florida’s No-Income-Tax Benefit (And Its Limits)

When You Owe Income Tax in Other States

Apportionment – How States Divide Your Income

State-Specific Considerations

Entity Structure Matters

Chapter 4: Employment Tax and Remote Workers

The Remote Work Revolution and Tax Implications

Withholding Requirements

Unemployment Insurance

Workers’ Compensation

Local Taxes (Yes, There’s More)

Chapter 5: Common Multi-State Scenarios for Entrepreneurs

Scenario 1: E-Commerce Business Selling Nationwide

Scenario 2: Remote Team Distributed Across States

Scenario 3: SaaS Company Selling Software

Scenario 4: Contractor/Consulting Business Working in Multiple States

Scenario 5: Amazon FBA Seller

Scenario 6: Growing Business Opening Second Location

Scenario 7: Trade Show/Event Business

Chapter 6: Technology and Systems for Multi-State Compliance

Manual vs Automated Solutions

Software Solutions Overview

Data You Need to Track

What Technology Can’t Replace

Chapter 7: Risk Management and Red Flags

Common Mistakes That Trigger State Audits

State Tax Department Enforcement

Penalties and Interest

Voluntary Disclosure Agreements

Audit Defense

Proactive vs Reactive Compliance

Chapter 8: When to Get Professional Help

The DIY Breaking Point

What to Look for in Multi-State Tax Support

How Milbrod & Hessel Approaches Multi-State Taxation

Getting Started

Conclusion

Key Takeaways

The Path Forward

Final Thought

Appendix A: Economic Nexus Threshold Quick Reference

Appendix B: State Income Tax Quick Reference

Appendix C: Multi-State Compliance Checklist

Sales Tax Compliance

Income Tax Compliance

Employment Tax Compliance

Record Keeping

Proactive Monitoring

Risk Assessment

Appendix D: Glossary of Multi-State Tax Terms

Appendix E: Useful Resources

State Tax Department Links

Industry Organizations

Software Providers

Professional Associations

Educational Resources

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