South Dakota v. Wayfair, Inc. is the 2018 Supreme Court decision that ended the rule requiring a business to have a physical presence in a state before that state could make it collect sales tax. In a 5–4 opinion, the Court held that a seller’s economic activity in a state, measured by sales volume or transaction count, is enough on its own to trigger tax collection duties. Every state that levies a sales tax has since written economic nexus laws under this framework, and remote sellers now face compliance obligations in states where they own nothing and employ no one.
What the Court Decided
Justice Kennedy wrote the majority opinion, joined by Justices Thomas, Ginsburg, Alito, and Gorsuch. The Court called the physical presence rule “unsound and incorrect” and overruled both of the cases that had established it.1Supreme Court of the United States. South Dakota v. Wayfair, Inc.
The majority treated the old rule as a judicial subsidy. Local retailers collected tax on every sale while online competitors selling the same goods to the same customers did not, and the legal system was effectively picking a winner. Modern businesses reach customers in every state without owning a single building, and the Court held that sustained, targeted economic activity of that kind satisfies the “substantial nexus” the Commerce Clause requires. The decision applied the four-part test from Complete Auto Transit, Inc. v. Brady (1977), concluding that economic activity above a reasonable threshold meets the nexus prong as well as physical presence ever did.2Constitution Annotated. Nexus Prong of Complete Auto Test for Taxes on Interstate Commerce
Why Physical Presence Was the Old Rule
The physical presence standard came from National Bellas Hess, Inc. v. Department of Revenue of Illinois (1967) and was reaffirmed in Quill Corp. v. North Dakota (1992). Both cases involved mail-order sellers whose only connection to customers in the taxing state was through mail or common carriers, and in both the Court held that the Commerce Clause barred the state from drafting those companies into its tax collection system.3Legal Information Institute. Quill Corp. v. North Dakota
The reasoning rested on the dormant Commerce Clause, the doctrine that states cannot impose rules that unduly burden interstate trade even when Congress has stayed silent.4Legal Information Institute. State Taxation and the Dormant Commerce Clause In Quill, forcing a catalog company to navigate thousands of local tax jurisdictions looked like exactly that kind of burden. By 2018, with e-commerce dominating American retail, the Court concluded the burden argument had flipped: the real distortion was the free pass remote sellers were getting.
The South Dakota Law at Issue
South Dakota’s 2016 Senate Bill 106 was written to force the fight. It required remote sellers to collect sales tax if, in the previous or current calendar year, they had more than $100,000 in gross revenue from sales delivered into the state or 200 or more separate transactions with South Dakota buyers.5South Dakota Legislature. 2016 Senate Bill 106
The statute barred retroactive enforcement, so the state could not pursue back taxes for periods before the law took effect. South Dakota was also a member of the Streamlined Sales and Use Tax Agreement, which uses uniform definitions and centralized registration to reduce the compliance load on out-of-state sellers. These features were deliberate, and the Court cited them approvingly when it upheld the law.6South Dakota Legislature. 2016 Senate Bill 106
What the Dissent Warned About
Chief Justice Roberts dissented, joined by Justices Breyer, Sotomayor, and Kagan. His objection was institutional rather than substantive. Roberts accepted that Quill might have been wrong but argued Congress held plenary power over interstate commerce and could have fixed the rule at any time with legislation designed around small-seller protections and uniform standards. By acting on its own, the Court cut off that process.1Supreme Court of the United States. South Dakota v. Wayfair, Inc.
Roberts also raised the practical burden on small businesses. The internet had let tiny sellers reach buyers across the country, and requiring someone selling handmade goods from a kitchen table to compute tax across more than 10,000 taxing jurisdictions could be devastating. As of 2026, Congress still has not passed comprehensive legislation addressing these concerns.
What Counts as a Constitutional Economic Nexus Law
The decision did not give states a blank check. The majority highlighted three features of South Dakota’s statute that pointed toward constitutionality, and those features have become the informal template every state follows.1Supreme Court of the United States. South Dakota v. Wayfair, Inc.
- Reasonable thresholds. The $100,000 or 200-transaction limits meant the law only reached sellers with meaningful activity in the state.
- No retroactive enforcement. The statute barred the state from reaching backward for tax periods before the economic nexus rule took effect, and no state has successfully imposed retroactive economic nexus obligations since.
- Simplified tax administration. South Dakota’s membership in the Streamlined Sales and Use Tax Agreement, which currently has 23 full member states, showed a commitment to reducing complexity through uniform rules.7Streamlined Sales Tax Governing Board. State Detail
The Court did not say these features are required in every case. It said they were evidence that South Dakota’s law passed the Complete Auto test. A state that adopted economic nexus without reasonable thresholds, or that tried to reach backward, would face a much harder time defending its law in court.
Economic Nexus Rules Across the States Today
Every sales-tax state now has an economic nexus law. The most common threshold is $100,000 in sales. A few states set the bar higher: California and Texas use $500,000, while Mississippi and Alabama use $250,000. Connecticut and New York require sellers to meet both a dollar threshold and a transaction count before collection duties start.
The Trend Away From Transaction Counts
South Dakota’s original two-pronged trigger used $100,000 in sales or 200 transactions, and most states copied that structure. The transaction count turned out to be a trap for small sellers: a business moving low-priced items could cross 200 transactions on barely $1,000 in revenue, and the cost of registering and filing would wipe out any profit from those sales. As of mid-2025, roughly half of states with economic nexus laws have dropped the transaction count entirely, including South Dakota itself, which eliminated its 200-transaction threshold effective July 1, 2025. The remaining states still use it as an alternative trigger alongside the dollar threshold.
Home Rule Complications
The United States has more than 12,000 separate sales tax jurisdictions, and in states with local sales taxes, rates and rules can vary block by block. In most states, the state government handles collection centrally and distributes revenue to localities, which keeps the system workable for remote sellers.
Colorado is the hardest state for compliance. It is the only state that allows individual localities to administer their own sales tax collection from out-of-state sellers. Colorado created a centralized portal called SUTS for registration and remittance, but local participation is voluntary and some jurisdictions remain outside it. Alabama took the opposite approach, letting remote sellers collect at a single statewide blended rate while the state handles distribution to local governments.
Marketplace Facilitator Laws
The ruling opened the door for marketplace facilitator laws, which move the sales tax collection duty from individual third-party sellers to the platforms that host them. If you sell through Amazon, eBay, Etsy, or a similar marketplace, the platform generally collects and remits the tax on your behalf.8Streamlined Sales Tax Governing Board. Marketplace Facilitator
That relief covers only sales made through the marketplace. If you also sell through your own website, at craft fairs, or anywhere else, you remain responsible for collecting and remitting tax on those sales. Some states also still require you to register and file returns even for marketplace sales, depending on local rules. The platforms themselves trigger facilitator obligations through the same economic nexus thresholds any seller faces, measured against aggregate sales their marketplace processes into the state, and the major platforms generally cross those thresholds in every state almost immediately.
Digital Products and Services
Wayfair involved physical goods, but its logic extends to anything a state chooses to tax. States disagree sharply about how to treat digital products, software subscriptions, and services. A SaaS subscription might be taxable in one state, exempt in another, and classified as something else entirely in a third. Some states only count sales of physical goods toward the economic nexus threshold, so a company selling only software might have millions in revenue from a state and still not trigger collection duties there because its sales don’t fit the state’s taxable-property definition. Digital businesses have to determine not just whether they’ve crossed a dollar threshold but whether their product even counts toward it under each state’s tax code.
What You Owe If You’ve Missed the Threshold
Once you cross a state’s threshold, your collection duty starts, and states can audit backward to measure what you should have collected. Penalties for failing to collect and remit sales tax generally run between 10% and 25% of the unpaid amount, with interest on top. Prolonged non-compliance pushes the total higher.
Sales tax is treated as a “trust fund” tax in most states, meaning the money you collect from customers is held in trust for the government. Failure to remit it can expose business owners personally, and a corporate entity or LLC will not always shield you. Officers, directors, and managers can be held individually responsible for uncollected or unremitted sales tax, and in some states that liability does not require any showing that the failure was intentional.
Voluntary Disclosure Agreements
If you discover you should have been collecting in states where you never registered, a Voluntary Disclosure Agreement is usually the right first move. A VDA is a written agreement under which you come forward, disclose back tax liability for a limited number of prior years (the lookback period), and pay what you owe plus interest. In return, the state waives some or all penalties and agrees not to assess tax for periods before the lookback window.9Multistate Tax Commission. Nexus FAQ
The Multistate Tax Commission runs a centralized program that lets you negotiate with multiple states at once. Your identity stays confidential until the agreement is finalized. To qualify, you cannot have previously filed returns in the state, received an audit notice, or had prior contact about a tax obligation there. The full back tax amount must be paid when the agreement is signed; the program does not offer payment plans. Even so, the penalty relief and limited lookback make VDAs much cheaper than waiting to be discovered.9Multistate Tax Commission. Nexus FAQ
Staying Compliant Going Forward
For any business selling across state lines, Wayfair created an ongoing monitoring job. Track your sales into each state, identify when you cross that state’s threshold, register for a sales tax permit (free in most states), start collecting the right tax on future sales, and file returns on the schedule the state assigns, usually monthly, quarterly, or annually based on volume.
Registration is straightforward. Managing rates, exemptions, and filing deadlines across dozens of states is not, which is why sales tax automation software has become effectively mandatory for any business with meaningful multi-state sales. If most of your sales go through major marketplaces, your burden is lighter because the platform handles collection and remittance, but you should still confirm the marketplace is collecting correctly and track whether direct sales give you independent nexus of your own.