Sales Tax Economic Nexus Guide: State Thresholds for 2026

Before 2018, a state could only require a business to collect its sales tax if that business had a physical presence there: an office, a warehouse, an employee, sometimes even a single traveling salesperson. That rule came from a 1992 case, Quill Corp. v. North Dakota, and it meant a mail-order or early ecommerce seller with no physical footprint in a state could sell there tax-free, legally.

South Dakota v. Wayfair, Inc. overturned that rule in June 2018. The Supreme Court held that a state can require sales tax collection based on economic activity alone, no physical presence needed, so long as the volume of business is substantial enough to establish a real connection to the state. South Dakota's own law, the one the Court upheld, set that bar at $100,000 in sales or 200 separate transactions in the state during the current or prior calendar year.

Every state with a sales tax adopted some version of an economic nexus law within about two years of that ruling. Most started close to South Dakota's original numbers. But the laws are not identical, they were not frozen in 2018, and several states have adjusted their thresholds since, including the specific question this guide focuses on: whether the 200-transaction count still applies. If you sell into multiple states, whether through your own site, a marketplace, or both, this is the law that decides when a new state's tax obligations start, not where your business is registered or where you ship from.

This guide covers the mechanics, the 2026 trend toward simpler dollar-only thresholds, marketplace facilitator rules, and the registration steps once you cross a line. It does not cover VAT, GST, or non-US consumption taxes; those are separate regimes with separate rules.

The model most states started with measures two things over a defined period, usually the current or immediately preceding calendar year:

• Gross sales into the state (sometimes taxable sales only, sometimes all sales including exempt ones, depending on the state's specific statute)
• The number of separate transactions, sales, or invoices into the state

Cross either number and the state considers you to have economic nexus, meaning you now owe sales tax collection and filing obligations there going forward, starting from the date you crossed the threshold or, in some states, the first day of the following month or quarter.

A few details that trip people up. First, most states count sales made through a marketplace facilitator (more on that below) toward your total for nexus purposes, even in states where the marketplace itself, not you, collects and remits the tax on those sales. Second, the look-back period is usually a rolling 12 months or the current and prior calendar year, not a fixed calendar year alone, so a strong holiday quarter can push you over a threshold mid-year. Third, "transactions" generally means the count of orders or invoices, not units sold, so a customer who buys one $30,000 item counts as one transaction, while a customer who buys 40 items in a single $200 order also counts as one.

The practical effect of the 200-transaction prong was to catch high-volume, low-dollar sellers, think a seller doing thousands of $8 orders, who would stay under $100,000 in sales for a long time while clearly doing sustained, repeated business in a state. That was also exactly the group state legislatures later decided was disproportionately burdened by the rule relative to the tax revenue it produced, which is the reasoning behind the trend in the next section.

A meaningful number of states have removed the transaction-count prong from their economic nexus law since 2018, leaving a single dollar threshold as the only test. The reasoning legislatures gave is consistent: a small business shipping a high volume of low-price items, craft goods, small parts, digital downloads under $10, was hitting 200 transactions while doing a fraction of the revenue a $100,000-threshold state intended to capture, creating a compliance burden without a matching amount of tax collected.

California and Texas never had a transaction count at all; both set a single dollar threshold from the start (California Department of Tax and Fee Administration, Out-of-State Retailers; Texas Comptroller Rule 3.286). South Dakota, the state whose law created the whole framework, removed its own 200-transaction test effective July 1, 2023, leaving a $100,000 sales-only threshold (South Dakota Department of Revenue). Other states have made similar changes on their own timelines. Because state legislatures amend these statutes without a single federal calendar, a specific state's current rule can change between when this guide was written and when you read it.

The practical takeaway is not a fixed list to memorize. It's a habit: before you register in any state based on a transaction count, confirm on that state's own department of revenue site whether the transaction-count prong is still in force, and at what number, for the current year. A state's official nexus or remote-seller FAQ page is the fastest way to check, and it takes a few minutes against a filing decision that can carry years of consequences if you get it wrong.

A small number of states, New York among them, use a different structure entirely: a dual test requiring both a dollar threshold and a transaction count to be met before nexus applies, rather than either one alone (New York State Department of Taxation and Finance). That structure has stayed stable longer than the single-prong states because it was designed differently from the start.

Separately from economic nexus, every state with a sales tax now has a marketplace facilitator law. These laws require a marketplace, Amazon, Etsy, Walmart Marketplace, eBay, eligible Shopify Payments configurations, and similar platforms, to calculate, collect, and remit sales tax on sales it facilitates for third-party sellers, in most states regardless of whether the seller itself has nexus in that state.

This matters for two separate reasons. First, if all of your sales in a given state flow through a marketplace that already collects and remits, you generally do not need your own sales tax permit or return in that state for those specific sales, because the collection obligation sits with the platform. Second, and this is the part sellers frequently miss, most states still count marketplace sales toward your economic nexus threshold, even though the marketplace is the one collecting the tax. So a seller doing $150,000 a year entirely through Amazon in a $100,000-threshold state has crossed the nexus threshold in that state, even if Amazon is handling every dollar of the actual tax collection there.

Why that distinction matters in practice: if you also sell through your own website or a second channel the marketplace doesn't cover, and your combined sales including the marketplace volume cross the state's threshold, you now owe your own registration and filing for the non-marketplace channel, even though your marketplace sales stay covered by the platform. Mixed-channel sellers, someone on Shopify and Amazon at once being the most common case, are the group most likely to get this wrong, usually by assuming Amazon's collection means the whole state is handled.

Each marketplace's help center documents which states it collects in and since when; Shopify, Amazon Seller Central, and Etsy's own tax pages are the fastest way to confirm your specific platform's current coverage state by state.

State nexus laws fall into a few recognizable patterns rather than 50 unique rules. Comparing the pattern types, not memorizing every number, is the more durable way to think about this:

• Dollar-only threshold. A single sales figure, commonly $100,000, with no transaction count at all. California and Texas use this model at a higher $500,000 threshold; a growing group of other states use it at $100,000. If your state is in this group, transaction volume never matters for nexus, only revenue.
• Dollar or transaction count (either/or). The original South Dakota-style test: cross either number and nexus applies. This is still the most common structure among states that have not updated their statute, though the specific transaction number some states use varies slightly from 200.
• Dollar and transaction count (both required). A smaller group of states, New York among them, require both conditions to be met before nexus applies, which is meaningfully harder to trigger than an either/or test at the same numbers.
• No sales tax at all. Five states, Alaska, Delaware, Montana, New Hampshire and Oregon, have no general state sales tax, so economic nexus for state sales tax purposes is not a question there (Alaska does allow local sales taxes in some municipalities, which run their own separate rules).

What this means practically: a business selling primarily low-priced items in high volume is affected far more by whether a state kept its transaction-count test than by the exact dollar figure, since the dollar threshold alone may never bind for that seller. A business selling a smaller number of higher-priced items is the opposite: the dollar threshold is what actually decides nexus, and a transaction count rarely matters.

The single biggest operational mistake in this area is treating nexus as a year-end question. Because most states measure a rolling 12-month period, or the current plus prior calendar year, a business can cross a threshold in October and owe registration from that point forward, well before any annual review would have caught it.

A workable tracker needs, at minimum: sales by state, updated monthly, broken out by channel (your own site versus each marketplace), running against each state's current threshold and look-back period. E-commerce accounting platforms and sales tax automation tools, TaxJar, Avalara, and similar vendors, build exactly this kind of dashboard by pulling data directly from Shopify, Amazon, and other sales channels, and most will flag a state once you're within a defined percentage of its threshold, not only after you've crossed it.

For a business selling through three or four channels across a dozen or more states, a spreadsheet updated quarterly is usually not fast enough to catch a threshold crossing before a filing deadline passes. For a smaller single-channel seller concentrated in one or two states, a simpler manual check each quarter can be adequate, provided someone actually owns doing it. The size of the business, not the complexity of the rules, is usually what decides which approach fits. What doesn't work at any size is discovering a threshold was crossed eight months ago during an unrelated bookkeeping cleanup or, worse, a state audit letter.

Once a state's economic nexus threshold is crossed, the general sequence looks the same across states, even though the specific portal and form differ:

1. Confirm the exact effective date. Some states require registration starting the date you crossed the threshold; others give you until the start of the next month or quarter.
2. Register for a sales tax permit through that state's department of revenue website, not a third-party site charging a fee for what the state provides directly.
3. Determine your filing frequency. States assign monthly, quarterly, or annual filing based on your sales volume in that state, and this can change year to year as your volume changes.
4. Set up tax collection on every channel selling into that state, your own site's checkout, and confirm marketplace channels are already covering their share correctly rather than assuming it.
5. File on time from your first assigned period, even if the amount collected is small; most states penalize late or missing returns more heavily than the underlying tax owed.

A state's registration form typically asks for your entity's EIN, formation state, business activity description, and the date you believe nexus began, so getting that date right before you file matters. Some states also ask whether you want to register retroactively to the actual crossing date or apply their voluntary disclosure process if you're catching up on a threshold crossed some time ago; a voluntary disclosure agreement can meaningfully reduce look-back exposure and penalties compared to waiting for the state to find you, and is worth discussing with a credentialed tax professional before you file if you're already past your effective date.

Take an ecommerce seller running a Shopify store and an Amazon Seller Central account, based in Ohio, selling a home goods product at an average order value of $45. By September, year-to-date sales look like this: Texas $210,000 across 4,600 orders, split roughly 60% Shopify and 40% Amazon; Iowa $118,000 across 2,600 orders, all through Amazon; and Vermont $34,000 across 750 orders, all through Shopify.

Texas: crossed the $500,000 threshold? No, $210,000 stays under it, so no nexus yet in Texas under its dollar-only test, regardless of the 4,600 transaction count, because Texas doesn't count transactions at all.

Iowa: $118,000 crosses Iowa's $100,000 dollar threshold. Nexus applies. But because all $118,000 came through Amazon, and Amazon is a registered marketplace facilitator collecting and remitting Iowa sales tax on the seller's behalf, the seller does not need a separate Iowa sales tax permit for those Amazon sales specifically; Amazon's own registration and collection covers them. If this seller opens direct Shopify sales into Iowa next year, those specific sales would need the seller's own registration, since the marketplace's collection only covers marketplace-channel sales.

Vermont: $34,000 stays well under most single-state dollar thresholds in the $100,000 range, so no nexus yet in Vermont on the numbers shown, though the seller should keep watching Vermont's own current published threshold since it, like every state, can be updated by its legislature.

The result: no new state registration is needed for this seller this year, but Iowa is worth flagging clearly in the tracker, both because the $100,000 threshold has already been crossed there and because any shift of Iowa volume from Amazon to the seller's own Shopify checkout would trigger a fresh registration requirement that doesn't exist today.

The failure pattern we see most often is not a business ignoring sales tax entirely. It's a business that registered correctly in its home state and one or two obvious ones, then never built a process for new states as sales grew. A few specific mistakes account for most of the real financial exposure:

• Assuming marketplace collection covers everything, when a second channel (your own site, a wholesale account, a trade show) pushed total state sales over the threshold without the marketplace's collection touching that second channel at all.
• Checking thresholds once a year at tax season instead of on a rolling basis, missing a mid-year crossing by months.
• Registering in a state before nexus actually exists, which creates an unnecessary filing obligation and cost with no corresponding tax benefit; register when the threshold is actually crossed, not preemptively out of caution.
• Treating a transaction-count number from an old blog post or a competitor's website as current, when that state may have since dropped or changed the test.
• Not accounting for exempt or wholesale sales correctly; some states include them in the threshold calculation, others exclude them, and getting this wrong in either direction changes the crossing date.

Most states offer a voluntary disclosure program specifically for businesses that discover a past-due nexus obligation on their own, before the state finds it through an audit or a data match with a marketplace's reporting. That program generally limits the look-back period and reduces or waives penalties; it is a materially better outcome than an assessment that arrives after a state-initiated audit, and it is worth raising with a credentialed tax professional the moment a past crossing is discovered, not after another filing season has passed.

Our sales tax filing and nexus support tracks your sales by state and channel against current published thresholds, flags a state before you cross it where possible, and builds the workpapers a return needs, exemption certificates matched to exempt sales, marketplace-collected sales separated from direct-channel sales, and a reconciliation between your bookkeeping and what each state's portal expects to see.

The returns themselves are prepared by our team and filed by you directly through the state's portal or by a registered filing partner, consistent with how every state, marketplace facilitator relationship, and filing frequency actually works; we do not represent that we independently file, sign, or lodge a return on a state's site as though we held that authority ourselves. Where a past nexus obligation surfaces during a review, that's a conversation for a credentialed tax professional about whether a voluntary disclosure approach fits your specific facts; we'll flag it and help assemble the numbers, not make that call unilaterally.

If you're not sure whether you already have nexus somewhere, the fastest first step is usually a state-by-state sales pull for the trailing 12 months against each relevant state's current threshold, which is exactly the exercise in the worked example above. That single report, more than any general rule of thumb, is what tells you where you actually stand today.