Last updated: 14 October 2026
What is HMRC’s VAT registration estimator, and should you rely on it?
HMRC’s VAT registration estimator is a free online tool on gov.uk that asks a few questions about your business and tells you whether you need to register for VAT, could register voluntarily, or don’t need to register. It is a helpful starting point. But it only gives an estimate based on your answers, so you should still check your rolling 12-month turnover against the £90,000 threshold, and the 30-day forward-looking test, yourself.
What the tool asks
- Whether your business is based in the UK
- Your taxable turnover in the last 12 months
- Whether you expect turnover to go over the threshold in the next 30 days alone
- Whether you sell goods or services that are exempt or outside the scope of VAT
- Whether you have taken over a VAT-registered business as a going concern
It then explains whether registration is compulsory and links to the registration service.
The two tests the tool applies
| Test | You must register if | Deadline |
| Backward look | Taxable turnover in the last 12 months is over £90,000 | Within 30 days of the end of the month it went over |
| Forward look | You expect taxable turnover in the next 30 days alone to exceed £90,000 | By the end of that 30-day period |
Taxable turnover includes standard, reduced and zero-rated sales, but not exempt or outside-the-scope sales.
Where the tool can mislead
- Mixed supplies: if you aren’t sure which of your sales are exempt, your answers may be wrong
- Overseas businesses: non-established businesses must register from their first UK taxable supply, with no threshold
- Reverse-charge services: services you buy from abroad may count towards your turnover
- Going concerns: the previous owner’s turnover can count
- Artificial separation: splitting one business into several to stay under the threshold can be challenged by HMRC
Example
A dog groomer has sales of £86,000 in the last 12 months and is about to sign a £6,000 contract with a kennel chain. The tool tells her she doesn’t need to register yet. But if her rolling turnover goes over £90,000 at the end of next month, she must register within 30 days. She sets a monthly reminder to check the figure.
Voluntary registration
The tool may say you can register voluntarily. That can be worth it if you sell mainly to VAT-registered businesses, or if you make zero-rated sales and want to reclaim VAT on costs. It may not suit businesses selling to consumers, because prices effectively rise by 20%.
Next steps
- Use the estimator for a quick check
2. Track rolling 12-month turnover monthly
3. Ask an accountant to confirm the VAT treatment of your sales
4. Register online once you know your effective date, and keep a copy of the confirmation
Frequently asked questions
Is the estimator’s answer binding?
No, HMRC decides based on the actual facts.
What if I register late?
You owe the VAT from the date you should have registered, plus possible penalties.
Do I include sales outside the UK?
Generally not, unless they are UK taxable supplies.
Can I deregister if turnover falls?
Yes, if it’s expected to be £88,000 or less.
Related: VAT registration calls from HMRC and VAT threshold.
Talk to Accotax
Want this handled for you? Our team at Accotax can help with VAT registration. See our VAT accountants service, or contact us for a free, no-obligation quote.
This page is general guidance based on HMRC rules for the 2026/27 tax year, checked against gov.uk on 14 October 2026. It is not personal advice, so speak to an accountant about your own situation.
