QUICK ANSWER
Handling sales tax comes down to five steps: figure out where you have nexus (a taxable connection to a state), register for a sales tax permit in each of those states before you collect, charge the correct rate at the point of sale, file returns on the schedule each state assigns you — even when you owe nothing — and automate as soon as you sell in more than a couple of states. Most single-location businesses only deal with their home state; e-commerce sellers can trip economic nexus thresholds (commonly $100,000 in sales into a state) without ever leaving home, which is where software earns its keep.
Key Takeaways
- Nexus decides everything — physical presence (location, employees, inventory) or economic activity (commonly $100,000 of sales into a state) creates the obligation to collect.
- Register before you collect — collecting sales tax without a permit is illegal in most states, and collected tax is never your money; treat it as a liability from day one.
- Marketplaces collect for you — Amazon, Etsy, and eBay handle collection as marketplace facilitators, but you may still need to register and file in some states.
- Zero returns still count — missing a filing deadline triggers penalties (often $50+ or a percentage of tax due) even for months with no sales.
Sales tax in 2026: what actually creates your obligation
Sales tax is a state and local tax on retail sales of goods (and, in many states, some services), collected by the seller and remitted to the government. Forty-five states plus DC impose one; Alaska, Delaware, Montana, New Hampshire, and Oregon don’t have a state-level sales tax, though some Alaska localities do. Your obligation to collect in a state exists only where you have nexus. Physical nexus comes from a storefront, office, warehouse, employees, or inventory in the state — including inventory a fulfillment service stores there for you. Economic nexus, the rule that reshaped e-commerce, kicks in from sales volume alone: most states use a $100,000 annual sales threshold, several large states use $500,000, and many states have dropped their old 200-transaction tests. Rates are a combined stack of state plus local rates, ranging from about 4% to over 10% depending on the jurisdiction.
1. Map where you have nexus
Start with the obvious: your home state and anywhere you have people, property, or inventory. Then check economic nexus: pull last year’s sales by state from your e-commerce or POS reports and compare against each state’s threshold. Recheck quarterly if you’re growing — crossing a threshold usually obligates you to register within a defined window (often 30–90 days or by the next transaction).
2. Register for permits before collecting
Register with each state’s revenue department (online, usually free or under $50) to get your sales tax permit and filing frequency assignment. Don’t collect before you’re registered — states treat unpermitted collection as fraud — and don’t register in states where you have no nexus, because registration creates filing obligations that don’t go away until you formally close the account.
3. Charge the right rate on the right products
Configure your POS or shopping cart to apply the combined state and local rate. Most states are destination-based for remote sales (the buyer’s address sets the rate), which is why a single state can have hundreds of rate combinations. Also check taxability: groceries, clothing, SaaS, and services are taxed differently state by state — SaaS alone is taxable in roughly half the states. If you sell on marketplaces, confirm which channels collect for you so you don’t double-charge.
4. File and remit on schedule — every time
States assign monthly, quarterly, or annual filing based on your volume, and deadlines cluster around the 20th of the following month. File even for zero-sales periods. Keep collected tax in a separate sub-account so it never looks like spendable cash — commingling sales tax is one of the fastest ways small businesses dig unfixable holes, because unremitted sales tax survives bankruptcy and can attach to you personally.
5. Automate once you pass two or three states
Manual multi-state compliance stops being worth your time quickly. Tools like Avalara, TaxJar, and the tax engines built into Shopify and QuickBooks calculate rates, track nexus thresholds, and auto-file returns for roughly $20–$100+/month depending on volume. A useful rule: when filing takes more than two hours a month or you’re registered in three or more states, automation is cheaper than your time — and far cheaper than penalties.
| Situation | Typical Obligation | What to Do |
|---|---|---|
| Single location, in-person sales | Home state only | Register once; POS applies local rate |
| E-commerce, ships nationwide | Home state + states over ~$100k sales | Track thresholds quarterly; register as crossed |
| Sells only via Amazon/Etsy | Marketplace collects | Confirm registration/filing rules per state |
| Services or SaaS | Varies widely by state | Check taxability before pricing |
Recommended Resources
TurboTax Home & Business 2025 — Sales tax you remit isn’t income, but getting it recorded correctly feeds directly into a clean Schedule C or business return at filing time.
Accounting All-in-One For Dummies — Covers liability accounts and remittance workflows, the bookkeeping backbone that keeps collected sales tax separate from revenue.
Frequently Asked Questions
What happens if I should have been collecting sales tax and wasn’t?
You owe the tax whether or not you collected it — states assess uncollected sales tax against the seller, plus penalties (commonly 5–25% of the tax due) and interest. The good news is that every state with a sales tax also has a path back into compliance. If the exposure is small and recent, the simplest fix is to register now, start collecting, and file the back periods voluntarily; many states reduce or waive penalties for voluntary filers. If you’ve had nexus for years and the liability is meaningful — typically five figures or more — look at a Voluntary Disclosure Agreement (VDA), a formal program where you come forward anonymously through a tax professional, and in exchange the state limits the lookback period (usually 3–4 years instead of unlimited) and waives most penalties. What you should not do is wait: states share data with marketplaces, payment processors, and each other, and an assessment that arrives by audit letter comes with the full lookback and no penalty relief. Price the fix, pick the route that matches your exposure, and treat it as a one-time cleanup cost of doing business.