VAT Threshold UK: When Do You Need to Register for VAT?

When do you need to register for VAT in 2026?

You need to register for VAT when either your taxable turnover for the last 12 months goes over £90,000, or you expect it to go over £90,000 in the next 30 days alone. Some non-UK businesses must also register when they supply goods or services to the UK, regardless of turnover.

In practice, that usually means one of these situations:

• Your rolling 12-month sales total has just crossed £90,000.
• You have signed a contract or won work that will take you above £90,000 within the next 30 days.
• You are based outside the UK and are making taxable supplies in the UK.

How does the rolling 12-month VAT threshold work?

The rolling 12-month rule means you look back over the previous 12 months at the end of every month, not just at your year end. That is why businesses often miss the threshold when sales rise quickly in a short period.

For example, if your total taxable turnover first goes above £90,000 on 15 July, you still test the position at the end of July. If that is the first month-end where your last 12 months are over the threshold, you must register within 30 days of the end of that month.

Tip: Build a monthly taxable turnover check into your bookkeeping routine. The VAT threshold is a rolling test, so waiting until year end is one of the main reasons businesses register late.

What counts towards taxable turnover for VAT in 2026?

Taxable turnover is the total value of what your business sells or supplies that is not exempt from VAT. That includes standard-rated, reduced-rated, and zero-rated sales, even though zero-rated sales are charged at 0% VAT.

It can also include some less obvious items, such as goods you hire out, business goods used personally, gifts or barter transactions, certain reverse charge services, and some building work your business does for itself. Exempt income does not count towards the main threshold test.

Once you are registered, working out what VAT to charge is a separate question from whether your turnover forces registration. For the pricing side, see our VAT calculation guide.

Can you register for VAT below the threshold?

Yes, you can register voluntarily if your turnover is below £90,000. That can make sense if you want to reclaim input VAT on costs, work with VAT-registered clients, or avoid needing to change your pricing and invoices later when growth pushes you over the line.

Voluntary registration is often worth considering if:

• Most of your customers are other VAT-registered businesses.
• You have sizeable setup or stock costs with VAT on them.
• Your turnover is close to the threshold and rising.
• You want to look established when tendering for work.

It is not always the right move. If you mainly sell to consumers, adding VAT can affect your pricing, margins, or competitiveness.

For a full guide of how to keep VAT as low as possible, as well as when or when not to register, read our 101 on how to reduce VAT.

How long do you have to register after crossing the threshold?

The deadline depends on why you became liable. If you went over the threshold on a rolling 12-month basis, you generally register within 30 days of the end of the month when you crossed it. If you expect to exceed £90,000 in the next 30 days, you register by the end of that 30-day period.

The effective date matters because it is the point from which you should be charging VAT and keeping VAT records correctly.

If you’re concerned about the potential penalties from paying VAT late, you might find our guide on the VAT Late Payment Penalties a useful read.

How do you register for VAT with HMRC?

You can usually register for VAT online. After registration, HMRC issues a 9-digit VAT number, confirms your effective date of registration, and tells you when your first return and payment are due.

A simple process looks like this:

1. Confirm the date you became liable, or the date you expect to exceed the threshold.
2. Gather your business details and registration information.
3. Follow HMRC’s VAT registration guidance.
4. Wait for your VAT number and effective date confirmation.
5. Update invoices, record-keeping, and VAT treatment from the effective date.

For a full guide, see our comprehensive guide on registering for VAT.

What happens if you miss the VAT registration deadline?

Missing the deadline can mean HMRC treats you as registered from an earlier effective date, so you may still owe VAT on sales you made after that date. HMRC can also charge a failure-to-notify penalty if you do not tell it on time.

HMRC says it will not charge a failure-to-notify penalty if you had a reasonable excuse, the failure was not deliberate, and you told HMRC without unreasonable delay after the excuse ended.

If your turnover has now fallen and you no longer expect to stay above the limit, read our VAT deregistration guide before deciding whether to stay registered or cancel.

Which VAT scheme might suit your business?

The right VAT scheme depends on how you trade, how quickly customers pay, and how simple you want your reporting to be. The scheme does not change the need to register, but it can change how you account for VAT once you are in the system.

The Flat Rate Scheme uses a fixed percentage of gross turnover, while Cash Accounting lets you pay VAT when customers pay you. Annual Accounting reduces filing frequency to one return a year, but you still make instalment payments.

How Sleek helps with VAT thresholds and VAT registration

If your sales are moving quickly, the main risk is not the rate of VAT, it is missing the point where registration becomes compulsory. Sleek helps small businesses track turnover, register on time, choose a suitable VAT scheme, and keep returns and records on track once VAT kicks in.