VAT registration
You must register once taxable turnover for the previous 12 months passes £90,000.00. The rest of this page is the detail that costs people money: the rolling test, the gap between your effective date and your VAT number, and what late registration actually costs.
Updated 10 September 2026 · Threshold checked 10 September 2026
When you must register #
| Test | Trigger | Register by | Registered from |
|---|---|---|---|
| Backward look | Rolling 12-month taxable turnover exceeds £90,000.00 | 30 days from the end of that month | First day of the second month after crossing |
| Forward look | You expect to exceed it within the next 30 days | End of that 30-day period | The date you realised |
The backward test is a rolling 12 months, not your accounting year. At the end of every month you total the previous twelve. Your year end has nothing to do with it. Check your own figures month by month.
How to register for VAT #
- Sign in to your Government Gateway account, or create one. Most businesses register online.
- Give your business details: legal name, trading name, address, and the date you started trading.
- Give your tax references: your Unique Taxpayer Reference, plus your company registration number and Corporation Tax reference if you are a limited company.
- Give your turnover figures and the date you went over the threshold, or expect to.
- Give your bank details for repayments.
- Choose your accounting scheme if you want one, such as the Flat Rate Scheme, cash accounting or annual accounting.
A few situations cannot be done online and need a paper form, including some overseas businesses, VAT groups, and applying to register a division separately.
How long it takes #
HMRC's target is to process most registrations within 40 working days. A straightforward online application for a UK business often completes in two to four weeks. Applications that need extra verification, for example where HMRC wants evidence the business is genuinely trading, take considerably longer.
Processing times come from reporting by accountancy practices rather than a published HMRC service standard, so treat them as typical rather than guaranteed.
The gap nobody warns you about #
This is the practical problem with VAT registration and it catches almost everyone.
- You are liable for VAT from your effective date of registration.
- You cannot issue a VAT invoice until you have your VAT number.
- Those two dates can be weeks apart.
Showing VAT on an invoice before you have a number is not allowed. But the VAT is still due on those sales, so simply invoicing your old prices means absorbing 20% out of your margin.
What to do instead:
- Invoice the VAT-inclusive total, with no VAT line and no VAT number shown.
- Tell the customer a VAT invoice will follow once your number arrives.
- Reissue a proper VAT invoice once you are registered, so they can reclaim it.
Your customers will not enjoy the price rise, but it beats paying the VAT yourself. The invoice generator produces both versions.
Voluntary registration #
You can register below £90,000.00 if you want to. Whether you should depends almost entirely on who your customers are.
| Usually worth it | Usually not |
|---|---|
| You sell mainly to VAT-registered businesses, who reclaim the VAT anyway | You sell mainly to consumers, who cannot reclaim it |
| Your sales are zero rated, so you reclaim input VAT and charge none | Your costs are low, so there is little input VAT to reclaim |
| You have large VAT-bearing costs, such as equipment or stock | You would rather not deal with quarterly returns |
| Being registered signals scale to the customers you want | Your prices are already keen and cannot absorb 20% |
For a consumer-facing business, voluntary registration is effectively a 20% price rise or a 20% margin cut. There is no third option.
What registering late costs #
HMRC treats you as registered from the date you should have registered, not the date you got round to it. You owe VAT on everything sold since then, whether or not you charged it.
| Months late | Sales at £8,000/month | VAT now owed |
|---|---|---|
| 3 | £24,000.00 | £4,000.00 |
| 6 | £48,000.00 | £8,000.00 |
| 12 | £96,000.00 | £16,000.00 |
That assumes you treat the sales as VAT inclusive, which is the usual outcome because going back to customers months later for an extra 20% rarely works. Penalties sit on top.
After you are registered #
- Charge VAT on your taxable sales from your effective date.
- Keep digital records and file through Making Tax Digital compatible software.
- File a return, usually quarterly, and pay by the deadline.
- Show your VAT number on every VAT invoice you issue.
- Reclaim input VAT on business purchases, including some incurred before registration.
Working in construction? The domestic reverse charge changes who accounts for the VAT on most construction services between registered businesses. CIS and the reverse charge.
Coming back down #
Once taxable turnover falls below £88,000.00 you can ask to cancel. HMRC usually confirms within 40 working days. Cancellation is compulsory within 30 days if you stop being eligible altogether.
VAT registration: when to register #
VAT registration when to register has two answers, and only one of them is the famous one. You must register if taxable turnover over the last rolling 12 months has gone over £90,000.00, and separately if you expect to go over it within the next 30 days alone.
The forward-looking test is the one people miss. Winning a single contract that will take you past the threshold inside a month triggers registration immediately, before any of that money has been invoiced. The VAT threshold checker tests both.
Your VAT registration certificate #
The VAT registration certificate is what confirms you are registered. It shows your VAT registration number, your effective date of registration, and the date your first return is due. It appears in your VAT online account rather than arriving by post.
Keep it to hand. Suppliers setting you up on credit terms ask for it, contractors verifying you before applying the reverse charge ask for it, and your accountant will ask for it. The VAT registration date on it is the one that decides which of your invoices should have carried VAT.
Checking a VAT number #
A UK VAT registration number is nine digits, usually written with a GB prefix. Unlike almost every other tax reference, VAT registration numbers are public: HMRC runs a free VAT registration checker that confirms whether a number is valid and, if it is, the name and address registered against it.
That VAT registration search is worth running before you accept a large VAT invoice from a new supplier, and particularly in construction. If the number is not valid the VAT on that invoice is not reclaimable, and discovering it when HMRC asks is far more expensive than discovering it now.
VAT registration requirements and cost #
The VAT registration cost is nothing. There is no fee, and any service charging one is charging you for form-filling rather than for the registration itself.
The VAT registration requirements are mostly proof of identity and of trade: your business details, your Government Gateway ID, your bank account details and your turnover figures. A company also needs its company registration number and UTR; a sole trader needs their National Insurance number instead.
Checking a VAT number #
A VAT registration lookup is free and takes seconds. HMRC runs a service that confirms whether a VAT registration no is valid and, where the business has consented, shows the name and address it is registered to.
Use it before paying an invoice that charges VAT. A VAT registration number check protects you twice: it confirms the supplier is entitled to charge VAT, and it supports your own input tax claim if HMRC later queries it. VAT number verification on a large first invoice from a new supplier is five seconds well spent.
VAT registration online through your business tax account is the normal route to register, and VAT registration UK wide works the same way whichever nation you trade from.
Common questions #
When do I have to register for VAT?
Once your taxable turnover for the previous 12 months goes over £90,000, or as soon as you expect to go over it within the next 30 days. The backward test runs on a rolling 12 months rather than your accounting year.
How do I register for VAT?
Online through your Government Gateway account in most cases. You will need your business details, your Unique Taxpayer Reference, your turnover figures, your bank details and, for a company, your company registration number.
How long does VAT registration take?
HMRC aims to process most registrations within 40 working days, and straightforward online applications often complete in two to four weeks. Cases needing extra verification can take considerably longer.
Can I charge VAT before my VAT number arrives?
You must account for VAT from your effective date of registration, but you cannot issue a VAT invoice without a number. The usual approach is to invoice the VAT-inclusive amount, tell the customer a VAT invoice will follow, then reissue once the number arrives.
Can I register for VAT voluntarily?
Yes, at any turnover level. It makes sense if you sell mainly to VAT-registered businesses, or if you are zero rated and want to reclaim input VAT. It rarely makes sense if you sell to consumers, because your prices effectively rise by 20% or your margin falls.