VAT threshold planning calculator
The VAT registration threshold is based on a rolling 12-month total, not your tax year, which catches people out. Enter your numbers to estimate when you might approach the £90,000 line, so you can plan ahead instead of being surprised.
How the threshold actually works
You must register for VAT if your taxable turnover over any rolling 12-month period goes over £90,000, or if you expect it to go over £90,000 in the next 30 days alone. The rolling test trips far more businesses than people expect, because it is not measured against your accounting year. You can apply to deregister if turnover falls below £88,000.
If you cross the line, you generally must register within 30 days of the end of the month you went over, with registration effective from the first day of the second month after.
How to use the result
If you are within a few months of the threshold, plan early: decide whether to absorb VAT or raise prices, get your bookkeeping VAT-ready, and look at whether the Flat Rate or cash accounting schemes help. The worst position is crossing it by accident and finding you owe VAT you never charged.
VAT thresholds verified June 2026 from GOV.UK: register at £90,000, deregister at £88,000 (both unchanged since 1 April 2024). The time-to-threshold figure is a planning estimate based on a simple growth projection, not a forecast, and the rolling-12-month test depends on your actual month-by-month sales. Thresholds can change at fiscal events. This is not tax advice - speak to an accountant before registering.