Economic nexus by state is the set of rules that decide when an out-of-state seller has to register, collect, and remit sales tax in a state where it has no physical presence. Every state that imposes a sales tax now enforces these rules, and the most common trigger is $100,000 in annual gross sales, though the threshold reaches $500,000 in a couple of jurisdictions. Five states have no general sales tax, so economic nexus doesn’t apply there. The remaining 45 states and the District of Columbia each set their own dollar amount, their own measurement window, their own rules about which sales count, and their own deadline for when you have to start collecting after crossing the line.
The framework traces back to the 2018 Supreme Court decision in South Dakota v. Wayfair, Inc., which overturned the earlier physical presence rule from Quill Corp. v. North Dakota and let states reach remote sellers based on economic activity alone.1Supreme Court of the United States. South Dakota v Wayfair, Inc.2Justia. Quill Corp v North Dakota, 504 US 298 (1992) By 2020, every state with a sales tax had its own version on the books, and the resulting patchwork is what remote sellers have to work through jurisdiction by jurisdiction.
Where the Thresholds Land
A large majority of states use $100,000 in gross sales as the threshold. One state sets the bar at $250,000, and two use $500,000. No state currently goes below $100,000.
Many states originally paired the dollar figure with a transaction count, usually 200 separate sales, so a seller triggered nexus by crossing either limit. The transaction count was meant to catch sellers of low-cost goods moving high volumes, but in practice it swept in very small businesses that hit 200 orders long before they reached anything close to $100,000 in revenue. States have been pulling back from that approach. More than 15 states have eliminated their transaction thresholds since 2019, with several changes landing in 2024 and 2025. The states still using transaction counts are a shrinking minority.
The dollar threshold almost always refers to gross sales or gross receipts, not net profit and not taxable sales. That distinction matters. A business selling only exempt products, or a wholesaler whose customers all provide resale certificates, still counts every dollar of those sales toward the threshold in most jurisdictions. Crossing the line creates the registration and collection duty even when the seller ends up remitting little or no actual tax.
Which Sales Count Toward the Threshold
The categories of revenue included in the threshold calculation vary state by state, and the differences catch sellers off guard more often than any other part of the framework.
- Exempt sales of tangible goods are counted by most states. Selling only tax-exempt items does not keep you under the radar.
- Wholesale and resale transactions are counted in many states even when the buyer provides a valid resale certificate.
- Services are included in some states’ thresholds and excluded in others. A few states count only tangible personal property, which changes the picture entirely for service-based sellers.
- Marketplace sales are treated inconsistently. Some states exclude them from the seller’s individual threshold because the marketplace facilitator is already collecting the tax. Others include them, meaning platform sales alone can push you into a registration requirement.
The safest posture is to assume everything counts until you confirm otherwise for each specific state. Excluding a category of sales because you assumed it didn’t count is exactly the kind of error that shows up in an audit.
Measurement Periods and When Collection Has To Begin
Knowing the dollar amount is only half of it. You also need to know what window of time the state uses to measure. Most states look at the current or preceding calendar year, so you can trigger nexus based on last year’s total or a running total for the current year. A handful of states use different windows: four rolling sales tax quarters, a 12-month period ending on a specific date, or a trailing 12-month figure reviewed quarterly.
Once you cross the threshold, the clock starts. States handle the timing differently:
- Immediate collection. Several states expect tax on the very next transaction after you exceed the threshold. No grace period.
- A 30-day window is a common middle ground, with collection required by the first day of the month starting at least 30 days after the trigger.
- A 60-day window applies in a smaller group of states.
- Next calendar year. A few states only require collection starting January 1 of the year after the threshold is crossed.
A seller crossing the threshold in one state on October 15 might owe tax on the very next order shipped there, while another state wouldn’t demand collection until January 1. Watching your sales numbers continuously, not just at year-end, is the only reliable way to stay ahead of the states that require immediate action.
Marketplace Facilitator Rules
Every state with a sales tax has enacted marketplace facilitator laws requiring platforms like Amazon, eBay, Walmart, and Etsy to collect and remit sales tax on behalf of third-party sellers.3Streamlined Sales Tax Governing Board. Marketplace Facilitator State Guidance For a lot of small sellers this means the platform handles the tax and the seller never touches it. Genuinely helpful. Also a source of false security.
The complication is whether those marketplace-facilitated sales count toward your own economic nexus calculation. In states where they do, a seller running entirely through Amazon can exceed $100,000 in platform sales and trigger a registration requirement even though Amazon already collected every dollar of tax. The seller doesn’t owe additional tax on those sales, but the state still wants that seller on the books, and failing to register can lead to penalties even when no tax was actually owed.
Sellers using multiple platforms, or splitting between a platform and their own website, have to track total sales into each state across all channels. The marketplace handles tax only for orders placed through the marketplace. Sales through your own Shopify store, phone orders, and wholesale transactions remain entirely your responsibility.
Physical Nexus Hasn’t Gone Away
Economic nexus draws most of the attention, but a single physical connection to a state can trigger a sales tax obligation regardless of whether you’ve hit any dollar or transaction threshold. This is where sellers who think they’re too small to worry about nexus get blindsided.
The most common physical nexus trigger for e-commerce sellers is inventory stored in a third-party warehouse. If you use a fulfillment service that spreads your goods across warehouses in multiple states, you have physical nexus in every state where inventory sits. The fulfillment provider may move your stock without your explicit approval, and you may not always know which states hold your goods at a given moment. States actively obtain inventory records from fulfillment companies to identify sellers who should be registered.
A remote employee working from home in another state is another trigger. Even one person handling customer service, marketing, or sales support can establish physical nexus. Independent contractors doing similar work can create the same problem, though the rules vary. Other triggers include attending trade shows past a certain number of days, owning or leasing property, and delivering goods with your own vehicles.
Physical nexus also opens the door to state income tax. Federal law generally shields an out-of-state seller from state income tax if its only in-state activity is soliciting orders for tangible goods approved and shipped from outside the state.4Office of the Law Revision Counsel. 15 USC 381 – Imposition of Net Income Tax Storing inventory in the state goes beyond solicitation and blows through that protection.
SaaS, Digital Goods, and Services
The economic nexus framework was designed around tangible goods, and it shows when you try to apply it to software, digital downloads, streaming access, and cloud tools. Some states tax SaaS as a digital service. Others classify it as tangible personal property because the user receives access to something. Some treat it as exempt. A few draw different lines depending on whether the software is delivered under a license or a service contract.
The threshold calculation adds another layer. A few states base their threshold only on tangible personal property and exclude services entirely. A SaaS company selling $2 million in subscriptions into one of those states might have zero nexus there. The same company selling into a neighboring state that includes services would have to register and collect. There is no federal standard that resolves the inconsistency.
For any digital or service-based seller, two questions have to be answered for each state: does this state count my type of revenue toward the threshold, and if I have nexus, is what I sell actually taxable there? The answers frequently differ, which is why a SaaS company can have nexus in a state and owe no tax, or owe tax in a state where it lacks nexus to collect it.
Registering Once You Have Nexus
Once you’ve established economic nexus, you have to register for a sales tax permit before you can legally collect tax from customers. Most states handle registration through the revenue department’s online portal. You’ll typically need your federal Employer Identification Number, your legal entity name as registered in your home state, an industry classification code, and the date you first crossed the nexus threshold. The state uses that last item to set your first return due date and to determine whether any back-tax period exists.
Filing frequency depends on your estimated volume. High-volume sellers file monthly, mid-range sellers file quarterly, and low-volume sellers may file annually. You have to file a return for every period, even a period with zero sales and zero tax collected. Skipping a zero-dollar filing is one of the most common mistakes new registrants make, and it triggers penalties in most states. Some states will file an estimated return on your behalf and bill you for it until you submit the actual return.
Sellers with nexus in many states can save time using the Streamlined Sales Tax Registration System, a single free application covering all 24 member states.5Streamlined Sales Tax Governing Board. Sales Tax Registration SSTRS Non-member states still require direct registration, but covering two dozen states through one form removes a lot of the paperwork.
If You’re Already Behind: Voluntary Disclosure
A lot of businesses discover they’ve had economic nexus in a state for months or years before they noticed. Registering normally at that point effectively tells the state you should have been collecting earlier, which invites an assessment for the entire back period. A voluntary disclosure agreement is usually the better path.
Under a VDA, the business contacts the state (often through the Multistate Tax Commission, which coordinates the process for many states) and discloses the unpaid liability. In exchange, the state limits the lookback period to a set number of prior years rather than going back to the first day of the obligation, and it waives penalties in whole or in part. Interest on the unpaid tax is usually still owed.6Multistate Tax Commission. FAQ Lookback periods vary, but three to four years is common. One important exception: sales tax that was actually collected from customers and never remitted has to be paid in full regardless of the lookback limit, and penalty waivers may not apply to it.
The VDA process requires filing returns for the lookback period and paying the assessed amount. Compared to being found through an audit and assessed the full liability plus penalties from day one of nexus, a VDA saves real money. The catch: it has to be initiated before the state contacts you. Once an audit notice arrives, the voluntary disclosure option usually closes.
What Non-Compliance Costs
Ignoring economic nexus doesn’t make the obligation go away. States assess back taxes for the entire period you should have been collecting, plus interest that runs from the original due date of each unfiled return. Failure-to-file and failure-to-pay penalties typically run from 5% to 25% of the unpaid tax, depending on the state and how long the delinquency lasted. Some states also add flat-dollar penalties per unfiled return.
The exposure builds quickly. A business owing $3,000 per month in uncollected tax across a three-year lookback faces $108,000 in back taxes before interest and penalties are added. And because sales tax is a trust tax, meaning it’s money collected from customers on behalf of the state, some jurisdictions treat failure to remit it more seriously than ordinary tax delinquency. Officers and owners can face personal liability in certain states even when the business is a corporation or LLC.
The best protection is proactive monitoring. Review your sales into each state at least quarterly, track cumulative totals against each state’s threshold and measurement period, and register promptly when you cross the line. Registration is usually free or close to it, and compliance software costs less than a single state audit.