Owing Sales Tax in a State You Have Never Visited
A Supreme Court decision replaced physical presence with an economic threshold, so a seller can owe tax collection duties in a state purely by exceeding a sales figure there. Compliance became a substantial operational problem.
The Rule That Changed
For decades, a state could require a seller to collect sales tax only if the seller had physical presence in the state, meaning property, employees, or agents there.
The rule made administrative sense when it was decided and produced an obvious distortion as remote selling grew. A local shop collected tax and a catalogue or online seller shipping into the same state did not.
Technically the buyer owed use tax on the untaxed purchase, and almost nobody paid it, so the practical effect was that remote sales went untaxed.
In 2018 the Supreme Court overruled the physical presence requirement, holding that a state may require collection where a seller has substantial nexus established through economic activity.
What Replaced It
States adopted economic nexus thresholds, typically a dollar amount of sales into the state, a number of separate transactions, or either.
A common threshold pattern is a sales figure in the low hundreds of thousands or a couple of hundred transactions, though the specifics vary and several states have since removed or raised the transaction count element.
| Old Rule | Current Rule | |
|---|---|---|
| Trigger | Physical presence | Economic threshold |
| Seller with no state presence | No obligation | Obligation once threshold crossed |
| Jurisdictions to monitor | Where you have property or staff | All of them |
The transaction count threshold was the harsh one. A seller of low priced items could cross two hundred transactions in a state while generating a few thousand dollars of revenue there, and acquire a full compliance obligation for it.
Why Compliance Is Genuinely Hard
The difficulty is not the rate. It is that nearly everything varies by jurisdiction.
Rates vary by locality, not only by state, with thousands of separate taxing jurisdictions whose boundaries do not follow postal codes.
Taxability varies by product. Whether food, clothing, digital goods, or software as a service is taxable differs by state, and the definitions are inconsistent. Whether a given software product is a taxable good or a non taxable service has produced extensive dispute.
Exemption certificates for resale and exempt buyers must be collected, validated, and retained, with the seller liable if a certificate is invalid.
Filing frequency and format differ, so a seller registered in thirty states files on thirty schedules.
The Marketplace Shift
The compliance burden on small sellers was severe enough that states responded with marketplace facilitator laws.
Those laws place the collection obligation on the platform rather than on the individual seller for sales made through it. A marketplace with millions of sellers collects and remits, which is administratively far more efficient than each seller registering separately.
For a small seller operating only through marketplaces, the effect was to remove most of the burden. For one selling through both a marketplace and its own site, the obligation splits, and whether marketplace sales count toward the economic nexus threshold for direct sales varies by state.
The Related Obligations
The decision changed sales tax and it also drew attention to nexus concepts elsewhere.
Income tax nexus operates under different rules, and a federal statute protects sellers whose only activity in a state is soliciting orders for tangible personal property. That protection does not cover services or digital products, which is a growing gap.
Registration obligations follow tax registration in most states, meaning a seller registering for sales tax may also be required to register to do business, appoint a registered agent, and file annual reports.
Those secondary obligations are frequently discovered afterwards and carry their own fees and penalties.
The Practical Response
Businesses handle this through automation, since manual compliance across dozens of jurisdictions is not feasible.
Tax calculation services determine rates and taxability at transaction level, and filing services prepare and submit returns. Both are ordinary operating costs for any seller of scale.
The remaining judgement is where to register. A seller marginally over a threshold in a small state faces a compliance cost that may exceed the tax collected, and the decision to register is a cost benefit calculation with a compliance risk on the other side.
Voluntary disclosure programmes exist in most states, permitting a seller who discovers a past obligation to come forward with limited lookback and reduced penalties, which is the standard remedy for a business that grew across thresholds without noticing.
The Bottom Line
Replacing physical presence with an economic threshold ended a distortion that had let remote sellers avoid collection entirely, and it created a compliance obligation that scales with the number of jurisdictions rather than with the size of the business. Marketplace facilitator laws removed most of the burden for sellers operating through platforms, which is where the volume is. What remains difficult is a mid sized business selling directly across many states, which must track thresholds, taxability, and filing obligations that differ in every one of them.