Real story: What is nexus and when does your business owe sales tax in another state

You’re running a solid business in Florida. Sales are climbing. Then a customer asks if you can ship to Georgia, and you freeze. Do you owe sales tax there? What about Tennessee? Texas? The question that stops many small-business owners in their tracks is this: What is sales tax nexus, and when does your business actually have to collect and file sales tax in another state? The answer determines whether you’re legally compliant or facing unexpected exposure. This isn’t theoretical—it affects your bottom line, your filing requirements, and your audit risk. Let’s build your understanding from the ground up, so you can expand confidently without accidentally becoming a tax collector for states where you don’t belong.

Does this apply to your business in Florida?

Yes, if you sell tangible products or certain services across state lines. Sales tax nexus means your business has a sufficient connection to another state that you must collect and remit sales tax there, even if you don’t have an office. The Florida Department of Revenue defines nexus for Florida sellers; each state has its own rules. If you have a warehouse, employee, affiliate, or marketplace account in another state, you likely have nexus. Even drop-shipping or inventory stored there can trigger it.

What is sales tax nexus, and why it matters

Nexus is the legal or economic tie that connects your business to a state. Think of it as the threshold that says: “You have a relationship with this state, so you play by its sales tax rules.” Without nexus, you typically don’t owe sales tax; with it, you must register and file, whether you’re collecting tax or claiming exemptions. The trigger varies by state. Some care about physical presence (a warehouse, employee, or office). Others focus on economic activity (total sales, transaction count, or recurring customers). Since the 2018 South Dakota v. Wayfair ruling, many states now use economic thresholds instead of just physical presence. For Florida-based sellers, this means you may owe tax in states where you’ve never set foot, simply because your sales volume there crossed a state’s threshold.

The five main nexus triggers

Physical presence. You have an employee, office, warehouse, or affiliate in the state. This is the clearest trigger and applies in virtually every state.

Drop-shipping or inventory storage. You keep goods in a warehouse, fulfillment center, or third-party logistics hub in another state. The moment stock arrives there, nexus may exist.

Economic threshold (sales volume). You exceed the state’s revenue threshold—typically $100,000 to $500,000 annually, though each state differs. Once you cross it, you owe sales tax in that state for all future sales.

Marketplace account or affiliate channel. You sell through an Amazon, eBay, or Shopify store and store inventory in that state’s fulfillment network, or you have a commissioned sales rep operating there.

Regular or recurring services. You provide ongoing services (cleaning, consulting, repairs) to customers in another state. Some states treat this as sufficient nexus, especially if you have a regular client relationship.

How to check if you have nexus in another state

First, audit your operations. Ask yourself: Do I have anyone (employee, contractor, rep) working in this state? Do I store inventory there? Am I selling on a marketplace that fulfills from that state? Have I hit the state’s economic threshold for total sales? If yes to any, nexus likely exists. Next, check the target state’s Department of Revenue website. Most publish their nexus rules and thresholds online; they’re not hidden. Write down your state’s revenue limit and economic test. Then, compare your sales in that state to the threshold. If you’re trending toward it or already over, register for a sales tax permit—don’t wait. Finally, once you register, check if you owe sales tax retroactively. Many states don’t, but some do. This is where a quick email to the state’s customer-service line, or a call, can clarify your exposure before you file your first return.

Registering and filing in a new state

Once you’ve determined that nexus exists, registration is straightforward but state-specific. Most states offer online registration through their Department of Revenue website. You’ll need your Federal Employer Identification Number (EIN), principal business address, description of what you sell, and your expected monthly tax liability. Registration usually takes a few business days to a week. You’ll receive a sales tax permit number, a filing deadline, and filing frequency instructions. Most states require monthly or quarterly filing. Some have thresholds: file monthly if you owe over $X; file quarterly if under. The filing itself looks similar to Florida’s DR-15—you’ll report total sales in that state, taxable sales, tax collected, and any applicable credits or deductions. The process is walked through step by step in the Florida Department of Revenue role and function course. Once you have your permit, create a simple schedule to track when each state’s return is due. Use a calendar or a CRM to avoid missing deadlines—penalties for late filing are real and compound quickly.

The Florida sales tax structure and multi-state complications

In Florida, you pay a 6% state sales tax plus a county surtax. Each county’s surtax rate varies, so your combined rate depends on where your customer is located. Tangible personal property is taxable unless specifically exempt; services are not taxable unless listed in Florida Statute 212. When you sell into another state, that state’s rules replace Florida’s. If you sell tangible goods to a customer in Georgia, Georgia’s sales tax rate applies—not Florida’s. If you provide a service taxable in Florida but not in Georgia, you don’t owe tax in Georgia. This is the source of confusion: your home-state rules don’t follow you. Every state has its own taxability matrix. A service taxable in one state might be exempt in another. You cannot assume. The Florida Sales Tax Guide walks you through Florida’s rules in detail; use each state’s Department of Revenue site to understand their specific taxability rules before you start selling there. Many states offer nexus and taxability guides in plain English—use them.

Common mistakes multi-state sellers make

Assuming no nexus because there’s no office. Physical presence is not the only trigger. If you store inventory in a warehouse in Georgia or regularly sell to customers there over a sales threshold, you have nexus. Many sellers skip registration because they think an office is required, then get a notice from the state asking for back taxes. The fix: audit your operations annually. Track where inventory sits, where you have employees, and your sales in each state. Set a rule: any state where you exceed the published economic threshold, you register.

Collecting tax but not filing returns. You register, start collecting tax from customers, but then forget or delay filing. The state notices you’re collecting but not reporting. Penalties follow, plus interest on the unpaid tax. Filing is the second half of the equation; registration is only step one. The fix: on the day you register in a new state, add the filing deadline to a calendar or task manager. Set a monthly or quarterly reminder, depending on the state’s requirement. If you’re disorganized, use your CPA’s calendar or a bookkeeping service to track it for you.

Misclassifying products as exempt when they’re taxable in the target state. A product is exempt in Florida, so you assume it’s exempt everywhere. But Florida’s exemptions don’t apply in other states. You fail to collect tax, get audited, and owe back tax plus penalties. For example, certain equipment might be exempt in Florida for farming but taxable in another state for the same use. The fix: before you start selling a product category in a new state, confirm its taxability status in that state. Write it down. Train anyone handling orders to verify before assuming an exemption applies.

Ignoring marketplace nexus rules. You sell on Amazon or Shopify and store inventory in their fulfillment network. You don’t think you owe sales tax because you’re not a “business” in those states—you’re just using a service. But most states now consider marketplace nexus sufficient. Amazon also files returns on your behalf in many states, but you’re still liable for accuracy. If they file wrong or you owe but didn’t register, it’s your exposure. The fix: check Amazon, Shopify, or your marketplace’s tax documentation. Many now offer built-in sales tax collection and filing. Use it. And confirm you’re registered in states where the marketplace is collecting tax on your behalf.

Creating a multi-state sales tax schedule

If you sell in more than two states, a spreadsheet or simple filing calendar will save you. Create columns: State, Permit Number, Filing Frequency, Due Date, Last Filed, Next Due Date. Update it monthly. This becomes your “nexus inventory.” It also helps when you hire a bookkeeper or CPA—hand them this list, and they know exactly where you owe filings. For most small Florida businesses, this is manageable in a spreadsheet. As you grow, a sales tax platform (not an accounting app, but a dedicated sales tax tool) can automate tracking and even file for you. But even a spreadsheet beats scrambling on the 20th of the month wondering which states need returns.

When to bring in professional help

If you’re selling in two states, you can manage nexus compliance yourself with clear documentation. If you’re in five or more, or if your sales channels are complex (marketplace plus direct plus wholesale), consider outsourcing the tracking and filing to your CPA or a sales tax service. These professionals stay current on threshold changes, nexus rule updates, and filing requirements—something that shifts annually. Your role: ensure your sales data is accurate and categorized by state. Their role: file on time and keep you compliant. This partnership is much cheaper than a back-tax audit notice.

Frequently Asked Questions

What’s the difference between nexus and sales tax liability?

Nexus means you have a sufficient connection to a state and must register for a permit. Sales tax liability means you owe and must collect tax on sales to customers in that state. Nexus is the trigger; liability is the obligation. You can have nexus but not owe tax on specific sales if they’re exempt (e.g., resales, certain services). You cannot have liability without nexus.

Do I owe sales tax in every state where a customer lives?

No. You owe sales tax only in states where you have nexus. A customer living in California doesn’t trigger nexus unless you have a warehouse there, a sales rep, or you’ve hit California’s economic threshold. Most states’ thresholds are $100,000 to $500,000 in annual sales before economic nexus kicks in. Check each state’s rules.

What if I move inventory to a fulfillment center in another state? When do I register?

As soon as inventory arrives in that state, nexus exists. You should register before you start shipping from that location. If you’ve already shipped, register immediately and contact the state to ask whether you owe sales tax retroactively or only going forward. Many states are reasonable about this if you proactively register.

Can I drop-ship from a supplier in another state without owing sales tax there?

Not necessarily. If the supplier stores inventory on your behalf in their state, or you have an exclusive relationship, some states consider that nexus. If the supplier is independent and you simply order and they ship directly to your customer, nexus is less likely. The test is control and connection: if you manage the relationship or benefit from inventory in that state, nexus may apply. Confirm with that state’s DOR.

How often do state nexus thresholds change?

Economic thresholds are fairly stable, but nexus law itself changes. States adjust thresholds annually for inflation, and new court rulings or legislation can redefine nexus (as happened after the 2018 Wayfair decision). You should review your nexus status annually or when you hit a new sales milestone. Set a reminder each January to audit your operations and check each state’s current threshold.

This article is for general educational purposes and isn’t a substitute for advice from a licensed CPA or tax attorney. Rules vary by jurisdiction and change over time—always confirm current requirements with the Florida Department of Revenue or your advisor.

Building your nexus awareness into routine

Sales tax nexus isn’t complex once you map it. The mistake most small-business owners make is treating it as a one-time research project, then forgetting about it. Nexus rules shift. Your sales grow. A new state threshold gets crossed. Build a simple annual check into your routine: in December or January, review your sales by state, confirm which states you’ve hit economic thresholds in, and verify your current nexus status. If you’re unsure, email the state’s DOR. Most respond within a few days. Having a clear nexus inventory—where you owe tax, where you’re registered, and when each return is due—removes the guesswork and keeps you out of enforcement letters. That’s control, and that’s what builds a sustainable, compliant multi-state business.

For the Florida-specific rules behind this, our Florida sales tax guide breaks down rates, deadlines, and filing steps county by county.