When should you close a sales tax registration after your sales in a state fall below the threshold?

Falling below the threshold is not the end of the story

Economic nexus is measured over a window, typically the previous or current calendar year, and some states use a trailing twelve-month period. Dropping below the line in one quarter does not put you out; you have to be below for the whole measurement window the state uses. Read the state's rule closely, because the window decides the earliest date the obligation could actually end, and that date is often later than sellers expect. Related: Economic Nexus: A State by State Reality

Then there is trailing nexus. Several states require a seller who once had nexus to keep collecting for a defined period after the trigger disappears, sometimes through the end of the following calendar year. Physical presence that has ended, such as inventory that left the state, can carry a trailing period too. Closing the account before that period runs out leaves a gap the state can assess, and the state will not remind you of the rule before it does.

Keep reading: Economic Nexus: A State by State Reality, How to Know When You Are Approaching Nexus, Registering in a New State, Step by Step. See how ShopTaxie helps you sales tax nexus tracking and filing reminders.

Reasons to keep the account open

An open registration costs you one return per period, often a zero return. That is a small and predictable burden. If your sales are seasonal, or you expect to cross the threshold again next year, the churn of closing and re-registering is usually worse than filing zeros. Some states issue a new account number on re-registration, which fragments your filing history and confuses any later audit. Related: Registering in a New State, Step by Step

An open account also preserves your ability to collect tax legally. If you close it and then make taxable sales into the state, you may be collecting without a permit, which is a separate violation in many states. For a business with sales that hover near the line, keeping the account open and filing zeros is the conservative choice, and conservative is usually the right posture with a state you might need again. Related: Sales Tax Filing Frequencies Explained

Reasons to close

Close when the trigger is genuinely gone and unlikely to return: you stopped selling into the state, you pulled inventory out, the employee left, or your product line changed to something exempt. Close when the filing burden is real rather than nominal, such as a state that assigned monthly filing or one with separate local returns on top of the state return. Close when you have no customers there and no plan to acquire any.

Before you close, file every open period, pay any balance, and make sure the last return is marked as final. Keep your records for the state's statute of limitations. If the state has a trailing nexus period, set the closing date after it ends, not before. A final return filed too early is the most common way a closed account turns into an assessment a year later.

How to handle the practical side

Most states let you close online through the same portal you file in, or by marking a box on the final return. Some want a written request or a specific form. Whichever it is, save the confirmation. Update your billing system so tax stops being charged to customers in that state after the effective date, and be ready to explain the change if a customer asks why their invoice went down.

Keep the state in your nexus tracker with a status of closed and the closing date. If sales climb again, you want to see the moment you cross the threshold, not discover it after the fact. In our own tool we keep closed states visible for exactly this reason. The state is not gone, it is just quiet, and quiet states are where the next surprise usually comes from. Related: How to Know When You Are Approaching Nexus