The Small-Business Tax You're Probably Forgetting to Pay

Prepared by Debra Bradshaw, 10th May 2026

You file your sales tax returns. You pay your income tax. You figure out payroll tax. So when a state auditor sits down with your books, they go straight for the easy money, the tax most easily forgotten and most often misunderstood.

It's called Use Tax, and for many small businesses, it's the single largest unreported liability sitting on the books. Most owners don't know it exists. Most who know it exists don't know how to track it. And state auditors know exactly where to find it.

Here's what every business owner should understand about Use Tax, what it is, who owes it, and why "I've never paid it before" is the worst possible answer to give an auditor.

What Is Use Tax?

Use Tax is the companion to sales tax. They're two sides of the same coin: for any item a state considers taxable, some form of tax is always due, and that tax is paid by the final purchaser. Either the seller collects sales tax at checkout, or the buyer self-assesses use tax after the fact and remits it directly to the state.

Use Tax exists to close gaps in the sales tax system. If you buy a $5,000 piece of equipment from an out-of-state vendor who isn't required to collect your state's sales tax, your state still wants its cut. The obligation just shifts from the seller to you.

The rate is the same as sales tax. The reporting is on the same return, or on a separate Consumer Use Tax registration if your business doesn't otherwise file sales tax. The penalties for getting it wrong stack up fast.

Where Most Businesses Trip Up

A common assumption is that Use Tax was a problem solved by the 2018 Wayfair decision, which forced large online vendors to start collecting sales tax across state lines. Wayfair did fix a lot, your Amazon orders and most online office supply purchases now arrive with sales tax already calculated.

But Wayfair didn't eliminate Use Tax. It moved it. Today, the most common Use Tax exposure for small businesses lives in three quieter places:

1. Items pulled from inventory for non-sale use

This is the big one. You bought it tax-free under a resale certificate because you were going to sell it. Then someone on your team grabbed a few units for internal use, gave them away with a customer order, or took them home. The moment that happens, your business becomes the end consumer, and Use Tax is owed on what got pulled.

This trips up retailers, restaurants, convenience stores, and almost any business with inventory. A pack of batteries used in the office TV remote. A shirt off the rack worn to a trade show. Cleaning supplies and shop materials drawn from stock. Even shopping bags or to-go containers that the supplier didn't tax, if your business gives them away to customers, you're the end user.

2. Purchases from smaller vendors

Plenty of legitimate vendors fall below the thresholds that would require them to collect sales tax in your state. They're not doing anything wrong. But the tax obligation shifts to you as Use Tax.

3. The remaining out-of-state purchases

Less common since Wayfair, but still real, a vendor in a non-taxing state, a transaction between registration periods, a one-off direct B2B deal.

Why Auditors Love It

Here's a piece of inside-baseball worth knowing: in a state sales-and-use tax audit, reviewers spend most of their time in your accounts payable, not your sales records. They're looking for invoices without sales tax charged, and checking whether you self-assessed Use Tax on those purchases. If you didn't, every one becomes a finding.

It gets worse. A business that has never reported any Use Tax, while filing sales tax returns and showing meaningful out-of-state vendor activity, is a soft target. Reporting some Use Tax is more normal than reporting none. The all-zero pattern is one of the easiest things for a state to flag.

And findings on inventory-conversion items get extrapolated. Auditors take a sample, find a pattern, and apply that pattern across the entire audit period, turning a few months of unreported Use Tax into a multi-year assessment, plus penalties and interest.

What Good Use Tax Compliance Actually Looks Like

The good news is that staying compliant doesn't require fancy software or hours of monthly work. It requires one habit: a running log.

Hang a clipboard somewhere visible. Any time inventory gets pulled for a non-sale use, an employee writes it down, date, item, quantity, sale price. Any time an invoice comes in without sales tax charged, that goes on the log too. At the end of each filing period, the totals get tallied and submitted with the regular sales tax return.

That's it. Five minutes a week beats a year-end scramble. And a contemporaneous, date-stamped log is the single best defense against extrapolation in an audit, it's hard for an auditor to estimate Use Tax on rebuilt assumptions when the actual events are documented in the moment.

The Bottom Line

If your business buys equipment, supplies, or inventory, and especially if any of it ever gets used internally rather than resold, Use Tax probably applies to you. The amount is rarely the painful part. The painful part is when years of unreported activity surface during an audit with penalties and interest attached.

Most business owners don't need to become Use Tax experts. They need a simple capture system, a consistent habit, and an accountant who handles the rest.