How does sales tax nexus work for a Florida-based e-commerce seller shipping to other states?

If you’re running an e-commerce business out of Florida, you have nexus in Florida automatically. Physical presence in a state, whether that’s an office, a warehouse, or just where you live and work, creates nexus by default. That means you collect and remit Florida sales tax on taxable sales shipped to Florida customers.

The more complicated part is what happens with every other state you ship to.

Before 2018, remote sellers generally only owed sales tax in states where they had a physical presence. The Supreme Court’s South Dakota v. Wayfair decision changed that completely. Now states can require you to collect sales tax based purely on your economic activity there. This is called economic nexus. Most states have set thresholds around $100,000 in sales or 200 transactions within the state during a calendar year. Once you cross either threshold in a given state, you’re required to register, collect, and remit sales tax there.

Every state sets its own rules. Some use only a dollar threshold. Others use both dollar and transaction counts. A few have thresholds lower than $100,000. And the rates, filing frequencies, and product taxability rules vary from state to state. A product that’s taxable in Texas might be exempt in Pennsylvania. This is where multi-state compliance gets overwhelming fast.

One important thing many Florida e-commerce sellers overlook is marketplace facilitator laws. If you sell through Amazon, Etsy, Walmart Marketplace, or similar platforms, those marketplaces are required to collect and remit sales tax on your behalf in most states. That doesn’t mean you’re off the hook entirely. Sales you make through your own Shopify store or website still require you to handle sales tax management yourself. You need to track both channels separately to know where you’ve crossed thresholds on your direct sales.

Tools like TaxJar and Avalara can automate rate calculations, track your nexus exposure across states, and even handle filing. They integrate with most e-commerce platforms and take a lot of the manual work out of multi-state compliance. The cost is worth it once you’re selling in more than a handful of states.

The biggest risk is ignoring this altogether. States are actively going after remote sellers who should be collecting sales tax but aren’t. Back taxes, penalties, and interest add up quickly. If you’ve been selling across state lines for a while without tracking nexus, it’s better to get ahead of it now than to wait for a notice.

Working with a small business bookkeeper who understands e-commerce sales tax can help you figure out where you currently have nexus, get registered in the right states, and set up systems so you stay compliant going forward. This is one of those areas where getting it right from the start saves you real money and real headaches down the road.