I Crossed a Nexus Threshold — What Do I Do Now?

Step Zero: Establish When, Not Whether

Almost every guide on this topic starts with "register promptly". That is right only in the case where you crossed recently — and it is actively harmful advice in the case where you crossed eighteen months ago.

Verify You Actually Crossed

Thresholds sound simple and are measured inconsistently. Before acting, confirm three things about the specific state:

• The measurement period. Some states use the previous calendar year, others a rolling twelve months, others the current year to date². The same sales can cross in one framing and not another.
• What is counted. Gross sales, retail sales, or taxable sales only. A business selling largely exempt goods can cross a gross-sales threshold while owing very little tax.
• Whether marketplace sales count. Some states include them even though the platform collected the tax; others exclude them. This single rule frequently decides the answer — see marketplace facilitator laws.

The state-by-state thresholds are in the economic nexus guide, and the multi-state calculator will model your revenue against them.

Do Not Collect Before the Permit Arrives

The instinct on realising you have an obligation is to start charging tax immediately. Resist it. In most states, collecting sales tax without a permit is unlawful, because the money becomes trust funds the moment a customer pays it — and you would be holding public money with no registration and no way to remit.

The correct sequence, covered fully in how to register for a sales tax permit, is: register, receive the permit and filing frequency, then switch on collection.

The Gap Period Is Yours

Between crossing the threshold and going live there is a window of sales on which you did not charge tax but arguably should have. That liability is yours, not your customers' — re-invoicing them later is not realistic.

This is why speed genuinely matters once the sequence is right. Every week of delay adds sales to the gap, and the tax on them comes out of margin. It is also why threshold monitoring is worth automating: the cheapest version of this problem is the one you see coming.

Physical Presence Has No Threshold

One trap worth checking while you are here. Economic nexus has a threshold; physical nexus does not. Inventory in a state — including stock in a fulfilment warehouse — creates an obligation from day one, with no minimum sales.

Businesses that have carefully monitored revenue thresholds are sometimes already obligated in several states through a 3PL they never thought of as a presence. The inventory question is covered in the economic nexus guide.

Then Look at Every Other State

Crossing one threshold is a signal, not an isolated event. The growth that took you over in one state is usually pushing you toward others, and it is far cheaper to model all fifty once than to repeat this exercise quarterly as each one surprises you.

The Five-Step Plan

1. Verify the threshold was actually crossed. Confirm the state's measurement period and whether it counts gross sales, taxable sales or marketplace sales. Establish the exact date you crossed rather than the date you noticed.
2. Determine whether the crossing is recent or historic. If it happened in the current period, this is a straightforward registration. If it was months or years ago, treat it as a back-exposure problem before touching any registration form.
3. Assess back exposure before registering, if relevant. Where the crossing was historic, quantify the liability and evaluate a voluntary disclosure agreement while it is still available. Registering with a backdated effective date can close that door.
4. Register and wait for the permit. Apply through the state revenue department, then wait for the permit and assigned filing frequency. Do not collect tax in the interim.
5. Switch on collection and model the remaining states. Configure destination-based rates once permitted, then model every other state against its threshold, since the growth that crossed one usually approaches others.

Continue the compliance chain

• Economic nexus guide — the thresholds and how they are measured.
• Voluntary disclosure agreements — if you crossed a while ago.
• How to register for a sales tax permit — the mechanics once you are ready.
• Filing frequency & due dates — what begins the day the permit issues.
• What triggers a sales tax audit — how states find businesses that did nothing.