You must register for VAT if your taxable turnover for the last 12 months goes over £90,000, or if you expect your taxable turnover in the next 30 days alone to go over £90,000. Run both tests at the end of every month. If your turnover is below £90,000, you can still choose to register voluntarily.
The route, stop by stop
01Check at every month end
Add up your taxable turnover for the last 12 months. It is a rolling total, not your tax year.
Source 2
02Count the right sales
Taxable turnover includes zero-rated sales. Exempt sales and sales of business assets do not count.
Source 2
03Test 1: the last 12 months
Has your rolling total gone over £90,000?
YesRegister within 30 days of that month end.NoGo on to test 2.Source 1
04Test 2: the next 30 days
Do you expect sales in the next 30 days alone to go over £90,000?
YesRegister by the end of those 30 days.NoNot yet. Check again next month.Source 1
06Register online
Most businesses register online with HMRC. An accountant can also deal with HMRC for you.
Source 3
07Know your effective date
Test 1: the first day of the second month after you went over. Test 2: the date you realised.
Source 1
08Waiting for your number
You cannot show VAT on invoices yet, but you owe it from your effective date. Price with that in mind.
Source 3
10VAT number in hand
Show your 9-digit VAT number on every invoice and sign up for your VAT online account.
Source 3
How the two tests work
The first test looks back. At each month end, add up your taxable turnover for the previous 12 months. If it is over £90,000, you must register within 30 days of the end of that month.
The second test looks forward. If you expect sales in the next 30 days on their own to go over £90,000, for example because you have won a large contract, you must register by the end of that 30 day period.
What counts as taxable turnover
Taxable turnover is the total of your sales that are not exempt from VAT, including zero-rated sales. Exempt sales and sales of business assets are left out.
Common questions
Is the VAT threshold based on my tax year?
No. It is a rolling 12 month total that you check at the end of every month.
What happens if I register late?
HMRC registers you from the date you should have been registered. You owe VAT on sales from that date, even if you did not charge it to customers, and you may have to pay a penalty.
Can I charge VAT before I get my VAT number?
No. You cannot show VAT on invoices until you have your number, but you still owe VAT from your effective date of registration.
Sources
- GOV.UK: Register for VAT: when to register checked 3 November 2026
- GOV.UK: VAT Notice 700/1: who should register for VAT checked 3 November 2026
- GOV.UK: Register for VAT: how to register checked 3 November 2026
This Route Map is general information for UK small businesses, not personal advice. Rules and rates change, so check the sources before you act. If your situation is not straightforward, speak to your accountant.
