Your SaaS Might Owe Sales Tax in States You've Never Set Foot In

You run a SaaS out of your apartment. Your servers live in us-east-1, your customers are scattered across the country, and you have never once thought about sales tax, because you're one person selling software over the internet and that's obviously not a sales-tax situation. Then a notice arrives from a state you've never been to, informing you that you owe back sales tax, plus penalties and interest, on subscriptions you sold to people who happen to live there.

This is a real thing that happens to small software businesses. It's been happening since 2018, and it catches more founders every year, because nobody mentions it until you're already on the hook.

What changed in 2018

The case was South Dakota v. Wayfair. Before it, a state could only force you to collect its sales tax if you had a physical presence there, like an office, an employee, or inventory in a warehouse. The Supreme Court tossed that rule out. Now states can require you to collect based on "economic nexus," which mostly means: if you sell enough into the state, you have to register and collect there, even if you've never set foot in it.

Most states drew the line at $100,000 of sales into the state, or 200 separate transactions in a year. A few big ones set it higher. California, Texas, and New York use $500,000, and New York layers on a requirement of more than 100 transactions on top of the dollar figure. Cross the threshold, and you're expected to register, collect tax from your customers in that state, and send it in.

One trend worth knowing: the transaction-count trigger is dying off. More than fifteen states have dropped the 200-transactions rule, because it was dragging in tiny sellers who made a lot of small sales, and Illinois dropped it at the start of 2026. The dollar threshold is the one that's sticking around.

The question that's specific to software: is SaaS even taxable?

This is where SaaS gets genuinely weird, and where it stops behaving like selling physical goods. Crossing the economic nexus threshold only matters if the thing you sell is taxable in that state. For physical products, it nearly always is. For SaaS, it depends entirely on the state, and the states do not agree with each other even a little.

Some tax it. Some don't. There's no federal rule and no underlying logic you can reason your way to. Texas taxes SaaS, but classifies it as a "data processing service" and exempts 20% of the charge, so you end up taxing 80% of the subscription. New York taxes SaaS as the sale of prewritten software. Washington, Pennsylvania, and Massachusetts tax it too. Connecticut taxes it, but charges a reduced 1% rate when the customer is a business and the full rate when it's a consumer.

Then the states you'd expect to tax everything turn around and don't. California, of all places, does not tax SaaS, because there's no transfer of tangible personal property for its sales tax to grab onto. Florida doesn't tax it either.

And then there's the local wrinkle that makes the whole thing feel like a prank. Illinois doesn't tax SaaS at the state level, but the city of Chicago applies its lease transaction tax (roughly 9%) to it. So a customer in Chicago can be taxable even though "Illinois doesn't tax SaaS" is a true sentence.

Business customers can change the answer

One thing that often helps SaaS founders: plenty of states treat business buyers differently from consumers. Connecticut's 1% business rate is one version of this. Some states exempt purchases for resale, or carve out software used for business purposes. If you sell only to other businesses, your exposure can be smaller than a consumer app's. But smaller is not zero, you still have to work it out state by state, and "we're B2B" is not a free pass. Don't assume it exempts you.

What this means for a small SaaS, realistically

It's easy to read all that and panic, so let me bring it back down. If you're doing $4,000 a month spread across customers all over the country, you almost certainly haven't crossed $100,000 of sales into any single state. Economic nexus is measured per state, one at a time. You could do a million dollars of revenue split across 45 states and not trip a single threshold.

The founders who actually get caught tend to have concentration. A lot of customers clustered in one big state. Or a single chunky enterprise contract that, by itself, blows past $100,000 in somewhere like Texas. That's the profile to watch for.

So the move is not to run out and register in 45 states this afternoon. It's to know where your revenue concentrates, know which of those states tax SaaS, and notice when you're getting close to a threshold in one of them.

What to actually do

A sane plan for a small software business looks like this:

1. Find out where your customers are. Your Stripe dashboard can break revenue down by customer location. Go look at it.
2. For your top few states by revenue, check two things: how close are you to that state's economic nexus threshold, and does that state tax SaaS at all? Where both answers are bad, that's where you register first.
3. Once you cross a threshold in a state that taxes SaaS, register there, start collecting tax from those customers, and remit it. Stripe Tax handles the calculation, and SaaS-specific tools like Anrok and Numeral are built around exactly this problem.
4. If you discover you've owed tax somewhere for a while, don't try to quietly back-file years of returns yourself. That's a conversation with a CPA or a sales-tax specialist, and most states run voluntary disclosure programs that limit how far back they'll reach if you come forward.

The reassuring part is that software does the hard mechanical work here. Collecting the right tax once you're set up is mostly automated. The genuinely hard part is knowing when you're supposed to start, and that's a tracking problem you can put on autopilot before it becomes an expensive surprise.

Where QuickBiz fits

Sales tax registration isn't part of business formation, and I'm not going to pretend QuickBiz files your Texas returns for you. What formation gives you is the entity and the EIN that every one of those state registrations and tax tools will ask for on the first screen. If you're operating as a sole proprietor under your Social Security number and you suddenly need to register for sales tax in three states, having an LLC and an EIN in place first makes all of it cleaner. I walked through the rest of that early setup in the 7-day post-formation checklist.

This is also one of the clearest reasons to get a CPA involved once you have real revenue. Sales tax is cheap to handle early and genuinely painful to untangle late. If you're formalizing the business so you can register and collect without it being a mess, forming the LLC is step one and takes about five minutes.