Multi-State Sales Tax in 2026: What Texas Sellers Need to Know

Key Takeaways

• The 2018 Wayfair ruling gave states the green light to collect sales tax from out-of-state sellers based on economic activity alone.
• Most states have an economic nexus that triggers at $100K in annual sales. Texas’s threshold sits higher, at $500K.
• Miss a threshold and you’re on the hook for back taxes, penalties, and interest (whether you knew the rules applied or not).
• Software tools help with calculations. However, they won’t flag whether you should have registered in the first place.

The Wayfair Supreme Court Decision

For decades, the rule was physical presence: sales tax only followed you into states where you had a store, a warehouse, or someone on the ground. A 1992 Supreme Court ruling locked that in.

Then South Dakota v. Wayfair changed it. The 2018 decision said economic activity alone is enough for a state to require collection. No office. No warehouse. No physical footprint of any kind. Just sales above a threshold.

It was a significant shift – and the states moved fast. By 2020, nearly every sales-tax-imposing state had economic nexus rules in place.

What is an Economic Nexus?

An economic nexus is a threshold set by states for sales tax purposes following the 2018 Wayfair Supreme Court case. Economic activity or a number of transactions in a state above its economic nexus is subject to sales tax.

How the Wayfair Decision Affects Businesses Today

Six years after the Wayfair ruling, many businesses are still behind. Here’s the state of play for Texas sellers.

Running a business in Texas and selling to customers across state lines? Your sales tax picture is almost certainly more complicated than it was five years ago – and state enforcement is getting sharper.

The Numbers Behind Economic Nexus

$100,000 in annual sales into a state – or 200 separate transactions – is where most states draw the line. Cross either one and you’re on the hook to register, collect, and remit, regardless of whether you’ve ever been there.

Texas is the exception. The threshold here is $500,000. That means a lot of Texas sellers cross into nexus territory in other states long before their home state comes into the picture.

Why This Still Catches Sellers Off-Guard in 2026

Forty-five states. Forty-five sets of rules, with different rates, taxability definitions, and filing schedules. It’s a lot to stay on top of – and gaps show up even when businesses are actively trying.

A Few Situations that Come Up Regularly

• Gradual growth that crossed thresholds unnoticed. A business might have hit $100,000 in sales to California customers two or three years ago without realizing the threshold had been crossed. That’s potentially years of unfiled returns and growing exposure.

• Relying on software alone. Tax compliance software can calculate and file once you’re registered – but it doesn’t tell you that you should have registered. That gap is where most of the risk lives. If your business has been selling above the state tax nexus, there’s a strong possibility that you’ll be audited by the state sales tax board, and be exposed to unexpected extra taxes in that state. This is exactly the kind of thing professional sales tax consulting is built to catch.

• Product taxability surprises. Not every product is taxable in every state. Clothing is exempt in some states and fully taxable in others. Digital goods, software, food – the rules vary widely and have tripped up even experienced sellers.

Practical Steps for Texas Businesses

If you haven’t done a multi-state sales tax review recently, here’s a reasonable place to start:

1. Pull a sales-by-state report. See where your customers are and what you’ve sold them. At least a year’s worth of data.
2. Compare your sales against each state’s current economic nexus threshold. Rules get updated – what applied in 2022 may not hold today.
3. Check taxability, not just registration. Even in states where you’re already registered, confirm you’re applying the correct tax treatment to your specific product types.
4. Look into voluntary disclosure programs. Most states let businesses come forward before an audit, often with reduced penalties. Proactive beats reactive.

Enforcement is Getting Tighter

States are getting better at identifying businesses that should be registered – and more motivated to find them. Audits have increased. The tools states use to cross-reference sales data from marketplace platforms and payment processors have improved. And the “I didn’t know” window is closing – Wayfair is approaching its seventh year, which is long enough that most businesses have had time to hear about it.

Texas businesses that sell nationally face real exposure if their multi-state picture hasn’t been reviewed in a while. Small and mid-size sellers are often the most vulnerable, since they’ve typically grown fast enough to cross thresholds in several states but don’t have in-house tax teams watching for it.

The Upside for TX Sellers

The good news is that the framework is established. The rules are knowable and getting proactive – even if you’re starting late – is genuinely easier than cleaning up after an audit.

Start with the numbers. Find out where you’re selling and whether you’ve crossed any state thresholds. That one step tends to clarify everything else pretty quickly.