Economic nexus is the rule that lets a state require sales tax registration based on how much you sell into it, with no office, staff or inventory there. It is the reason a business operating entirely from one state can end up registered in a dozen.
This page explains how the test works and what feeds into it. For the current figure in each state, see economic nexus thresholds by state.
What Economic Nexus Is
A state sets a level of activity — a dollar figure, sometimes a transaction count — and any seller exceeding it becomes subject to that state’s sales tax rules. The connection is purely commercial. You never have to set foot in the state.
It is worth separating three questions that get confused constantly. Nexus asks whether a state can require you to register. Taxability asks whether what you sell is taxable there. Rate asks how much to charge. Having nexus does not mean everything you sell is taxable, and a business selling entirely exempt goods may still be required to register and file.
Economic Nexus After South Dakota v. Wayfair
Before 2018, a state generally needed physical presence before it could compel collection. In South Dakota v. Wayfair, Inc. the Supreme Court removed that requirement, and states moved quickly — nearly all of them adopted a sales-based standard within two years.
Two things are commonly misread. Wayfair did not create a national registration requirement, and it did not set a single threshold — each state writes its own. It also did not remove physical presence as a trigger. Physical nexus still applies in full, alongside the economic test.
Which Sales Count Toward Economic Nexus
This is where identical revenue produces different answers in different states.
- Taxable retail sales count everywhere.
- Exempt sales count in some states and not others. A state measuring gross sales includes them; a state measuring taxable sales does not.
- Wholesale and resale transactions are the biggest swing factor. A distributor selling mostly for resale can be far over the line in a gross-sales state and nowhere near it in a taxable-sales state.
- Marketplace sales are frequently counted toward your own total even when the platform remits the tax.
- Services count where the state taxes them, and states differ sharply on which services are taxable.
- Digital products — software, downloads, streaming, SaaS — are treated inconsistently, and this is one of the fastest-moving areas of state tax law.
Read each state’s own definition rather than applying one calculation everywhere. Getting this wrong in either direction is costly: registering where you had no obligation creates filing work you did not need, and missing a state creates liability you did not price.
Measurement Periods and Why They Differ
The same sales figure can put you over in one state and under in another purely because of the window being measured.
- Previous calendar year. A clean annual look-back. You know in January where you stand.
- Current or previous calendar year. The most common form, and it means a strong year can create an obligation mid-year.
- Rolling twelve months. The window moves continuously, so you can cross without any change in trading pattern.
- Rolling window reviewed quarterly. Used by a handful of states, including Illinois. The obligation is assessed at set checkpoints rather than continuously.
Economic Nexus for Ecommerce Sellers
Online sellers hit these rules earliest because their sales are geographically scattered by default. A few patterns recur.
Sellers of low-priced goods cross transaction counts long before dollar thresholds — in a state retaining a 200-transaction test, 200 orders at $15 carries the same consequence as $100,000 in sales. Sellers using fulfilment services may have physical nexus from stored inventory regardless of sales volume. And sellers on platforms often assume the platform’s collection ends the matter, which is usually wrong — see marketplace facilitator laws and sales tax nexus.
Economic Nexus Across Multiple States
Each state is assessed independently. There is no combined national figure, no reciprocity, and no single filing that covers several states. Twelve states means twelve registrations, twelve filing schedules and twelve sets of rules that can change without warning.
You can register in multiple states through one application rather than approaching each state separately.
When the Obligation Actually Begins
Crossing the threshold and being required to collect are not the same date. States vary — some require registration by the first day of the next month, others allow the following quarter, others tie it to the transaction that crossed the line. Since registration itself takes days to weeks, waiting until you have crossed usually means a gap during which you should have been collecting but were not.
That gap does not go away. States generally assess the tax you should have collected, plus penalties and interest, and the customer is long gone. Registering slightly early costs a few returns. Registering late costs the tax.
If you are already registered somewhere and want threshold activity in other states tracked as it happens, our sales tax compliance monitoring service handles it. If you have crossed a threshold and need the registration itself, start a sales tax registration.
Frequently Asked Questions
Is there one federal economic nexus threshold?
No. There is no federal sales tax and no national threshold. Each state sets its own figure, test and measurement period.
Does Wayfair mean every remote seller must register everywhere?
No. It permits states to require registration from sellers exceeding their thresholds. A seller below every threshold and with no physical presence generally has no obligation.
Do exempt or wholesale sales count?
It depends on the state. Some measure gross sales including exempt and wholesale transactions; others count only retail or taxable sales.
If sales fall below the threshold, does the obligation end?
Not automatically. The account stays open and returns remain due until you formally close the registration with that state.
SalesTaxApplication.net is a private filing service and is not a government agency. State agencies may allow businesses to handle these registrations directly. Rules vary and change — confirm your obligations with the state or a qualified professional. See also the sales tax nexus guide and the state sales and use tax directory.