If your business is growing, sooner or later you will ask: when do you need to register for VAT in the UK? It cannot wait until your year-end accounts, because HMRC tests your turnover every month. Miss the moment you cross the line and you can owe VAT on sales already made, at prices that never included it.
This article is general information based on GOV.UK and HMRC guidance, not tax advice. Check GOV.UK or a qualified accountant for your own situation.
The quick answer
According to GOV.UK, you must register for VAT if your taxable turnover goes over £90,000 — the current VAT registration threshold UK businesses work to.
There are two ways to cross that line:
- Your total taxable turnover for the last 12 months goes over £90,000.
- You expect your taxable turnover to go over £90,000 in the next 30 days alone.
You do not have to register if you only sell VAT-exempt or out-of-scope goods or services, and below £90,000 you can still choose to register — voluntary registration.
What taxable turnover means
Taxable turnover is not your income or profit: GOV.UK defines it as the total value of everything you sell that is not VAT exempt or “out of scope”. Costs are not deducted first — £95,000 of taxable sales with heavy expenses is over the threshold.
What counts towards the threshold
GOV.UK’s list of what is included covers:
- standard-rated, reduced-rated and zero-rated goods and services
- goods you hired or loaned to customers
- business goods you used for personal reasons
- goods you bartered, part-exchanged or gave as gifts
- services received from businesses in other countries that you had to “reverse charge”
- goods and services subject to the domestic reverse charge
- building work over £100,000 that your business did for itself
The trap is zero-rated sales: VAT is charged at 0%, but they are still taxable supplies and still count. A business selling mainly zero-rated goods crosses the threshold as surely as one charging the standard rate.
What does not count
- Exempt supplies. HMRC’s examples include insurance, providing credit, certain education and training, and the services of doctors and dentists.
- Out-of-scope income. GOV.UK’s examples include goods or services bought and used outside the UK, statutory fees such as the London congestion charge, hobby sales, and charity donations given for nothing in return.
- Sales of capital assets. VAT Notice 700/1 says you do not include capital assets you have sold, such as buildings, equipment or vehicles — except land or buildings you have opted to tax, where a non-zero-rated sale must be included.
Misclassification is how businesses drift over the threshold unnoticed — check your own sales before assuming they are excluded.
The rolling 12-month test
The first test looks backwards. At the end of every month, add up your taxable turnover for the previous 12 months. If the total has gone over £90,000, you must register.
It is a rolling 12 months — any period ending this month — not your tax year or accounting year. A few strong months can push you over long before your year end, and annual checkers can be months late before they realise.
GOV.UK’s example: on 15 July, your taxable turnover for the last 12 months reaches £100,000 for the first time. You must register by 30 August, and your effective date of registration is 1 September.
The next-30-days test
The second test looks forwards, and usually catches businesses that have just won a large contract. You must register if, at any point, you realise your taxable turnover will go over £90,000 in the next 30 days alone.
You have to register by the end of that 30-day period, and your effective date of registration is the date you realised — not the date the money arrives.
GOV.UK’s example: on 1 May, you arrange a £100,000 contract, to be paid at the end of May. You must apply by 30 May, and your effective date is 1 May. VAT is due on that contract from the day you agreed it. Keep a note of when any such contract was agreed.
Deadlines after you cross the threshold
| Test | Deadline to register | Effective date of registration |
|---|---|---|
| Rolling 12 months: turnover went over £90,000 | Within 30 days of the end of the month in which you went over | First day of the second month after you went over |
| Next 30 days: you expect turnover to go over £90,000 in the next 30 days alone | By the end of that 30-day period | The date you realised you would go over |
VAT Notice 700/1 confirms these deadlines. It adds that if you take over a business as a going concern, you must tell HMRC within 30 days of the transfer, and register if the combined taxable turnover of both businesses is over the threshold.
If you only went over temporarily
GOV.UK says you can apply for a registration “exception” if your turnover goes over only temporarily. HMRC will consider it and write to confirm; if they refuse, they will register you. You must apply — you cannot decide a spike does not count. If most of what you sell is zero-rated, an exemption from registration is also possible, but only with HMRC’s permission.
One group has no threshold: businesses based outside the UK that supply goods or services to the UK must register regardless of turnover, GOV.UK says.
Registering late: what happens if you register for VAT late?
Registering late does not move your start date. GOV.UK states that if you register late, you must pay VAT on any sales made since the date you should have registered. VAT Notice 700/1 adds that HMRC will register you from the date you were liable, however late you tell them, and you must account for VAT from that date even if you never charged it.
That is the expensive part: if prices never included VAT, it comes out of what you took. One offset exists — VAT on costs you incurred, where you hold VAT invoices, subject to the normal rules.
On top of the VAT, GOV.UK says you might need to pay a penalty, depending on how much you owe and how late your registration is. VAT Notice 700/1 explains that, for liabilities arising on or after 1 April 2010, this penalty is charged under the failure to notify rules in Schedule 41 of the Finance Act 2008. Percentage bands in older articles belong to the earlier, pre-April 2010 regime — do not rely on them.
If you find you crossed the threshold months ago, register now. Delay makes the bill and the penalty position worse, never better.
Should you register voluntarily? Pros and cons of voluntary registration
Below £90,000, GOV.UK confirms you can choose to register, if you are in business making, or intending to make, taxable supplies. If all your supplies are exempt, you cannot register.
You also choose your registration date, and can apply to backdate it by up to four years, VAT Notice 700/1 says. Choose carefully — HMRC will not normally let you change it afterwards.
Possible advantages
- You can reclaim VAT on purchases, from your effective date. Subject to conditions in HMRC’s VAT guide, that can include VAT on goods bought up to four years earlier (not used up or sold) and on services supplied not more than six months earlier. Businesses with heavy VAT-bearing costs — stock, equipment, software — gain most.
- It may not make you dearer to business customers, who can normally reclaim the VAT you charge as their input tax.
Possible disadvantages
- Prices to the public may rise, or your margin may fall. Customers who cannot reclaim VAT — ordinary consumers, unregistered businesses — must pay it on top, or you absorb it, and most goods and services carry the 20% standard rate, GOV.UK says.
- You take on ongoing admin: a VAT Return for every tax period, even with nothing to pay or reclaim, plus digital record-keeping.
Selling mainly to the public on tight margins? Staying unregistered is often simpler — model your own numbers first.
VAT for sole traders vs limited companies
There is no separate threshold: VAT for sole traders follows the same rules as for limited companies — same £90,000 threshold, tests and deadlines. Registration follows the business’s taxable turnover, not its legal form.
What differs is whose registration it is, and the details GOV.UK asks for. A sole trader registers as an individual, providing a National Insurance number, an identity document, bank details and a Unique Taxpayer Reference if they have one. A limited company registers in its own right, providing its company registration number, business bank details, its Unique Taxpayer Reference, and details relating to Corporation Tax, Self Assessment and PAYE.
Still choosing? Our guide to sole trader vs limited company in the UK covers the wider differences.
What happens after you register
Charging VAT
From your effective date of registration you can charge VAT on sales and reclaim it on purchases. GOV.UK says you will receive a nine-digit VAT registration number, which must appear on all invoices you raise, plus confirmation of your registration date and first return details.
One gap needs care: you cannot include VAT on invoices until your number arrives, even if your effective date has passed. GOV.UK explains you can meanwhile raise prices to cover the VAT owed. VAT Notice 700/1 adds that you can tell VAT-registered customers you will send VAT invoices later, and should send them within 30 days of the number arriving, at the correct rate — most goods and services are standard-rated, some reduced-rated or zero-rated.
Keeping records
VAT Notice 700/1 says to keep records of all business sales and purchases, plus a note of VAT charged and paid for each return period — your VAT account. GOV.UK states VAT records must be kept for six years.
Returns, payments and Making Tax Digital
Your VAT Return to HMRC — usually every three months, GOV.UK says — reports VAT charged to customers against VAT paid to other businesses. You pay the difference, or HMRC usually repays you if you paid more than you charged. A return is due every tax period, even with nothing to pay or reclaim.
Filing is digital: on registration, HMRC will sign your business up to Making Tax Digital for VAT, unless exempt. VAT Notice 700/1 explains this means digital records and returns submitted using compatible software, with updates every quarter. GOV.UK also says to sign up for a VAT online account when your number arrives. An agent can file for you, but responsibility stays with your business.
A simple monthly check you can do
One habit, repeated at each month end, keeps you safe:
- Total the month’s taxable sales, excluding anything exempt or out of scope. Online sellers can take this from their shop’s sales reports — see our guide to how to start an online shop in the UK on setting up those records.
- Add up the last 12 months, using a running list where the oldest month drops off each time.
- Compare with £90,000. Well below? Carry on. Close? Plan pricing, cash flow and software before you cross.
- Look ahead 30 days for contracts or orders that could exceed £90,000 alone — the forward test runs from the day you realise.
- Act inside the deadline if either test is met.
Five minutes at month end is a cheap price for avoiding a backdated VAT bill.
Frequently asked questions
What is the VAT registration threshold UK businesses must watch?
GOV.UK states it as taxable turnover of more than £90,000, tested over the last 12 months or the next 30 days. Below £88,000, you can choose to cancel your registration.
Is the threshold based on profit or on my tax year?
Neither. It is based on taxable turnover — the value of what you sell that is not exempt or out of scope, before costs — over any rolling 12 months, checked monthly.
Should I register for VAT voluntarily below £90,000?
Possibly, if you buy heavily from VAT-registered suppliers and sell to VAT-registered customers, who can reclaim the VAT you charge. It is less attractive if you sell mainly to the public, because prices may rise or margins absorb the VAT. Run your own numbers first.
What happens if I register for VAT late?
HMRC registers you from the date you should have registered. You must pay VAT on sales from that date, even though you never charged it, with an offset for VAT on costs where you hold invoices. GOV.UK adds that you might pay a penalty, depending on how much you owe and how late you are.
Do zero-rated sales count towards the threshold?
Yes. Zero-rated sales are taxable supplies charged at 0%, and GOV.UK includes them in taxable turnover. Only exempt and out-of-scope sales are excluded, plus sales of capital assets. If most of your supplies are zero-rated, you can ask HMRC for an exemption from registration — permission is required.
Sources
All figures and rules in this article were taken from the following GOV.UK and HMRC pages, checked November 2026:
- GOV.UK — Register for VAT: When to register for VAT — https://www.gov.uk/register-for-vat/when-to-register-for-vat
- GOV.UK — How VAT works (including VAT thresholds) — https://www.gov.uk/how-vat-works
- GOV.UK — Register for VAT: How to register for VAT — https://www.gov.uk/register-for-vat/how-register-for-vat
- HMRC — Who should register for VAT (VAT Notice 700/1) — https://www.gov.uk/government/publications/vat-notice-7001-should-i-be-registered-for-vat/vat-notice-7001-should-i-be-registered-for-vat
- GOV.UK — Charge, reclaim and record VAT: When not to charge VAT — https://www.gov.uk/charge-reclaim-record-vat/when-not-to-charge-vat
- HMRC — Late VAT registration penalty (VAT Notice 700/41) — https://www.gov.uk/guidance/late-registration-penalty-for-vat-notice-70041
Reminder: this article is general information, not tax advice. Thresholds and rules can change — always confirm the current position on GOV.UK or with a qualified accountant for your own circumstances.
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