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What Is Sales Tax Nexus?
Sales tax nexus is the legal connection between a seller and a state that obligates the seller to register with the state, collect sales tax from customers in that state, file periodic returns, and remit the collected tax. Before 2018, nexus was almost entirely a question of physical presence, an office, employee, warehouse, or stored inventory. The sales tax nexus calculator on this page evaluates both the old physical presence test and the newer economic nexus test on a state-by-state basis so multi-state sellers can see where they have obligations today and where they are likely to trigger them soon.
Nexus is determined per state, not nationally. You can have nexus in one state and not in the neighboring state with identical sales volume because the thresholds and rules differ. The tool above lets you add each state where you sell, enter the prior twelve months of revenue and transaction count, and indicate whether you have any physical connection. The output flags the states where you have nexus, the states approaching the threshold at more than eighty percent, and the states where you are well below the line. For a deeper look at the rate side of the equation once you do register, our sales tax calculator shows how local rates layer on top of state rates.
Nexus matters because the penalties for not collecting are paid out of your pocket. If you have nexus and do not register, you owe the state every dollar of tax that should have been collected, plus interest and penalties, even though you cannot legally go back to past customers to recover it. A focused sales tax threshold calculator helps you avoid that scenario by surfacing obligations the moment they appear.
South Dakota v. Wayfair and the Rise of Economic Nexus
The modern landscape of sales tax nexus is defined by the 2018 Supreme Court decision in South Dakota v. Wayfair, Inc. Before Wayfair, the controlling precedent. Quill Corp v. North Dakota (1992), required physical presence before a state could compel an out-of-state seller to collect sales tax. The Wayfair Court held that the physical presence rule was unsound and that a state may impose collection obligations on remote sellers based on economic and virtual contacts alone. The South Dakota law at issue used a threshold of $100,000 in sales or 200 transactions per year, and the Court found that standard constitutional. Read the full opinion at Cornell Law School's Legal Information Institute, which hosts the Supreme Court's official Wayfair decision.
Within two years of Wayfair, every state with a sales tax, plus the District of Columbia, had adopted an economic nexus rule. Most copied the South Dakota framework of $100,000 in sales or 200 transactions. The economic nexus calculator in this tool encodes every state's current rule, including the notable exceptions: California, Texas, New York at $500,000, and a smaller group at $250,000 such as Alabama and Mississippi. New York pairs its $500,000 revenue test with a more-than-100 transaction requirement using an AND combinator rather than OR, and Connecticut uses an AND test as well.
A separate but related development since Wayfair is the marketplace facilitator law. These statutes require platforms such as Amazon, Etsy, eBay, and Walmart to collect and remit tax on third-party sales they process. In every state with sales tax, marketplace sales generally do not count toward your own nexus threshold. The U.S. Census Bureau's State Government Tax Collections survey is a useful supplement for understanding how sales tax revenue and marketplace collection have evolved by state since Wayfair.
Physical vs Economic Nexus. How Each Test Works
Physical nexus is triggered by a tangible connection between your business and the state. Classic triggers include an in-state office or store, an in-state employee or independent contractor performing services on your behalf, inventory stored in the state, including at third-party fulfillment centers like Amazon FBA, trade-show or pop-up activity, and ownership of real property. Each of these creates nexus regardless of revenue. The state sales tax nexus rules at the physical level vary in detail but the categories are consistent across most states. Sellers using fulfillment networks frequently discover they have inventory in five to fifteen states they have never visited.
Economic nexus is the post-Wayfair test based purely on sales volume. It looks at either revenue, transaction count, or a combination, measured over a defined lookback window, usually the previous or current calendar year. The thresholds differ by state and the sales tax nexus calculator above stores all of them. Importantly, economic nexus does not turn off once you cross. Once triggered, you remain a registered seller and continue to file returns until you formally close the account, even in years when your sales drop below the threshold.
The two tests operate independently. If you have a single employee in Pennsylvania, you have nexus there even if you sell only $500 a year in Pennsylvania. If you sell $250,000 into Massachusetts but have never set foot there, you have nexus through the economic test. The Wayfair decision itself is the underlying authority for each state's economic nexus standard, and states have since layered their own lookback windows and effective dates on top of it.
State-by-State Sales Tax Thresholds
Most sales tax states use the South Dakota benchmark, $100,000 in sales or 200 transactions per calendar year, but a meaningful number do not. California, Texas, and Tennessee use a $500,000 revenue test with no transaction trigger. Alabama, Mississippi, and a few others use $250,000. New York uses a unique combination of $500,000 plus more than 100 transactions, requiring both before economic nexus is triggered. The multi state sales tax calculator here applies each state's actual rule so you do not over-register or under-register based on a single national rule of thumb.
Five states have no general sales tax at all: Delaware, Montana, New Hampshire, Oregon, and Alaska. The first four collect zero sales tax statewide and have no economic nexus threshold to track. Alaska is a special case. There is no statewide sales tax, but many cities and boroughs have joined the Alaska Remote Seller Sales Tax Commission and apply a $100,000 or 200-transaction threshold at the local level. The tool flags these NOMAD states separately so you can focus filing effort where it matters. For broader business entity and tax planning, our LLC vs S-Corp calculator helps decide which structure minimizes federal and self-employment tax once you cross into multiple jurisdictions.
Several states have updated their thresholds since the original Wayfair year. South Dakota itself dropped the 200-transaction trigger in 2023 and now uses a revenue-only test. Other states have raised or lowered dollar amounts or clarified whether wholesale, exempt, and marketplace sales count toward the threshold. The sales tax nexus calculator tracks the published rules in effect now and should be revisited each time you do an annual nexus review, ideally each quarter for fast-growing businesses.
What to Do When You Trigger Nexus
Once the sales tax nexus calculator flags a state in red, the path forward is well defined. First, register for a sales tax permit through the state department of revenue, usually an online process that takes fifteen to thirty minutes. Second, configure your e-commerce platform, point-of-sale system, or sales tax automation software. Avalara, TaxJar, Anrok, or similar; to start collecting tax at the destination rate for that state. Most states use destination-based sourcing, meaning the rate depends on where the buyer is, not where you are. Third, file your first return on the schedule the state assigns. Monthly is most common for higher-volume registrants; quarterly or annual is common at the lower end.
Plan for ongoing compliance cost. The calculator above uses $100 to $300 per state for one-time registration, $50 or more per state per year for filing software and fees, and four to twenty hours of annual filing labor per state depending on volume. Most growing multi-state sellers find that automation pays for itself by the fifth or sixth state because the marginal hour cost of preparing returns by hand quickly exceeds software subscription cost. Beyond sales tax, layering registrations in many states often pulls you into income tax nexus as well, check our quarterly tax calculator to plan estimated payments alongside sales tax compliance.
Finally, monitor states where you are approaching the threshold. The calculator flags any state where you are above eighty percent on either revenue or transactions but not yet over. These are the states that will likely require registration in the next quarter or two. Pre-registering before you cross is rarely necessary, but knowing which states are next lets you budget for the filing software, plan the operational changes to your checkout, and avoid late penalties. For the wider picture of where these tools fit inside your back office, explore all our business financial calculators covering pricing, profitability, and tax planning for multi-state operators.