Sales Tax Nexus: The Rules Every Peptide Seller Needs to Know

Quick question. Your peptide company is based in Texas, and you ship a vial to a customer in Ohio. Who gets the sales tax? If your answer is nobody, or maybe just Texas, it is the wrong one, and it is the kind of wrong that stacks up to real money before anyone tells you. So let’s fix that today.

Back in 2018, a Supreme Court case called South Dakota v. Wayfair changed the rules for online sellers. Before Wayfair, you only had to collect sales tax in states only where you had a physical presence. After it, states won the right to make you collect based on your sales volume alone, even in a location you have never set foot. That is the change that matters here.

There are two ways you can owe sales tax in a state. The first is physical nexus. This is the old rule, and it is simple. If you have a presence in a state, you collect tax there. A presence means an office, employees, or, and this is the big one for peptide sellers, inventory. If your product sits in a warehouse or a third-party fulfillment center in another state, you have physical nexus there. Use a fulfillment service and your inventory may be spread across several states without you realizing it, quietly creating a tax obligation in each.

The second is economic nexus, the one Wayfair created. Once your sales into a state cross a certain line, you must register and collect there, no physical presence required. The most common line is $100,000 in sales into a single state, though it varies more than you would think. Some states also count the number of transactions. Others, like California and Texas, set the bar higher at $500,000. And the rules keep moving. Several states dropped their transaction counts just this year. The goal is not to memorize all fifty. The goal is to know the line exists, and that you can cross it without noticing.

Here is how the trouble builds. You launch. Sales grow. Maybe one product catches on. Before long you have done $120,000 in sales into a state you have never visited, and you blew past their threshold months back. You were supposed to collect tax that whole time. You did not. Now you owe that money out of your own pocket, plus penalties and interest, because you cannot go back and bill past customers.

That is the frustrating part. Nobody sends you a warning when you cross the line. The obligation just grows in the background until a state notices, or until you go to sell your business and a buyer’s due diligence digs it up. And it will get dug up.

Does the research use only label get you out of this? No, it does not. Sales tax applies to the sale of tangible personal property. Your vials are tangible property. How they are labeled, or what a buyer intends to do with them, does not change the fact that they are physical goods sold to someone in a taxing state. That is a completely separate question from the FDA side of your business.

Now the good news, because I do not want to leave you spooked. This is manageable when you watch it. Track your sales by state from the start. Know which states you are creeping up on. Register and collect once you cross a threshold, and set that tax money aside so it never feels like yours to spend. Modern sales tax software plugs right into your store and flags you as you approach a line. It is not expensive, and it beats a surprise assessment by a mile.

None of this is about dodging anything. It is about knowing the rules have teeth before they cost you. Now you do.

By Melissa Diaz, CPA, Co-Owner & Partner, High Rock Accounting