Sales Tax Nexus Calculator
Since the Supreme Court's 2018 ruling in South Dakota v. Wayfair, online sellers must collect and remit sales tax in states where they exceed economic nexus thresholds, even without a physical presence. Most states set the threshold at $100,000 in sales or 200 transactions per year. Enter your annual sales and transaction count for a specific state to check whether you have triggered economic nexus and are obligated to register and collect sales tax.
How economic nexus works
Nexus triggered if: Sales in state >= Sales Threshold OR
(Transactions in state >= Transaction Threshold AND state has transaction test)
Example (South Dakota, $100k / 200 transactions): Sales $95,000 (below $100k threshold) but 210 transactions (above 200 threshold). Nexus is triggered by the transaction count test.
What to do once nexus is triggered
- Register for a sales tax permit with the state's Department of Revenue before collecting tax.
- Determine the correct tax rates for each locality where you ship (most states have local rates in addition to state rates).
- Set up your e-commerce platform or accounting software to collect the correct tax at checkout.
- File sales tax returns on the schedule required by each state (monthly, quarterly, or annually).
- Consider using the Streamlined Sales Tax program if you sell in multiple member states.
Frequently asked questions
What is economic nexus?
Economic nexus is the sales tax obligation created when a seller reaches a state's sales or transaction threshold, regardless of whether the seller has a physical presence in the state. It was established by the Supreme Court's 2018 decision in South Dakota v. Wayfair, Inc.
What thresholds trigger economic nexus in most states?
Most states follow the South Dakota model: $100,000 in sales or 200 separate transactions in a 12-month period. Some states have higher sales thresholds (California, New York, Texas use $500,000) or have eliminated the transaction count test.
Which states have no sales tax?
Five states have no statewide sales tax: Delaware, Montana, New Hampshire, Oregon, and the District of Columbia does not count as a state. However, some Alaska local jurisdictions have local sales taxes.
What period is used to measure the thresholds?
Most states measure economic nexus over the current or prior calendar year (12-month period). Some states use a rolling 12-month period. Check the specific state's Department of Revenue for the exact measurement period.
What happens if I exceed the threshold?
You must register for a sales tax permit in that state, collect the applicable sales tax from customers, file regular returns, and remit collected tax to the state. Failure to do so can result in back taxes, penalties, and interest.
Official sources
- South Dakota v. Wayfair, Inc.: Supreme Court Opinion (2018).
- IRS: Sales Tax Resources for Small Business.
- Streamlined Sales Tax Governing Board: SST Program.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.