The £90,000 rule: what "rolling 12 months" actually means
The single biggest misunderstanding about UK VAT is that the threshold applies to your tax year or your accounting year. It does not. You must register for VAT when your total taxable turnover for the previous 12 months goes over £90,000, and that 12-month window moves forward every single month. This is set out on GOV.UK's VAT registration guidance.
In practice this means that at the end of every month you should add up the taxable turnover for that month plus the previous 11. A business that bills £7,000 a month steadily will never cross the line (£84,000 a year). A business that bills £4,000 a month for eight months and then lands three £20,000 projects has sailed past £90,000 and probably has not noticed.
The deadline is tight. If you cross the threshold at any point during a month, you have 30 days from the end of that month to register, and your effective date of registration is the first day of the second month after you went over. Cross £90,000 on 15 July, register by 30 August, and you are VAT-registered from 1 September. Every sale you make from 1 September onwards has VAT in it, whether or not you remembered to add it to the invoice.
The 30-day forward look test that catches people out
There is a second, separate test, and it is the one that generates the nastiest surprises. If you expect your taxable turnover to exceed £90,000 in the next 30 days alone, you must register immediately, and your effective date of registration is the date you formed that expectation, not the date the money arrives.
A one-off contract worth £110,000 signed on 3 March makes you VAT-registered from 3 March. There is no grace period and no run-up. If you invoice that contract without VAT because "I have not hit the threshold yet", the £110,000 is treated as VAT-inclusive and you owe HMRC £18,333 out of your own pocket unless the client agrees to pay the VAT on top. Get the registration in before you issue the invoice.
What counts as taxable turnover (and what does not)
Taxable turnover is everything you sell that is not VAT-exempt or outside the scope of UK VAT. That includes:
- Standard-rated sales (20%)
- Reduced-rated sales (5%)
- Zero-rated sales (0%), which still count towards the threshold even though you charge no VAT
- Goods you hire or loan to customers, and business goods used for personal reasons
- Reverse-charge services you buy in from overseas suppliers
It excludes VAT-exempt supplies (insurance, most financial services, certain education and healthcare), and it excludes sales of capital assets such as a van you no longer need. If you are a sole trader with two unrelated trades, they are still one person for VAT: the turnover is added together.
The zero-rated point deserves emphasis. A children's clothing retailer with £150,000 of sales charges 0% VAT on almost everything, but is still required to register, and gets a very pleasant result: they reclaim input VAT on rent, stock and overheads while charging nothing to customers.
UK VAT rates and thresholds at a glance
These are the figures in force for the current year, taken from GOV.UK VAT rates, the Flat Rate Scheme guidance and the HMRC penalty guidance.
| Item | Figure | Notes |
|---|---|---|
| Standard VAT rate | 20% | Most goods and services |
| Reduced rate | 5% | Domestic fuel, children's car seats, some renovations |
| Zero rate | 0% | Most food, books, children's clothes (counts towards threshold) |
| Registration threshold | £90,000 | Rolling previous 12 months, or expected in next 30 days |
| Deregistration threshold | £88,000 | Expected taxable turnover in the next 12 months |
| Flat Rate Scheme: join | £150,000 or less | Expected taxable turnover, excluding VAT |
| Flat Rate Scheme: must leave | Over £230,000 | Total income including VAT, tested on each anniversary |
| Flat Rate first-year discount | 1% off your rate | First 12 months of VAT registration only |
| Limited cost business rate | 16.5% | Applies if goods cost under 2% of turnover or under £1,000 a year |
| VAT return deadline | 1 month + 7 days | After the end of each accounting period; payment due the same day |
| Late return penalty | £200 | At 4 penalty points for quarterly filers (5 monthly, 2 annually) |
| Late payment: first penalty | 3% at day 15, plus 3% at day 30 | Nothing if paid or a plan agreed within 15 days |
| Late payment: second penalty | 10% a year, daily | From day 31 until the balance is cleared |
What registration actually costs you: the pricing maths
VAT is not your money and it is not a tax on your profit. But whether it costs you anything depends entirely on who your customers are.
If you sell to VAT-registered businesses, registration is close to cost-free. You add 20% to your invoices, your client reclaims it, and you start reclaiming the VAT on your own laptop, software, accountant and fuel. Your net income is unchanged and your costs fall by roughly a sixth.
If you sell to consumers or to VAT-exempt bodies (private clients, small landlords, insurance firms, most healthcare), the 20% is a real haircut. A hairdresser charging £60 for a cut cannot usually push the price to £72 overnight. If the price stays at £60, that is now VAT-inclusive: £50.00 for you and £10.00 for HMRC. The formula matters, so learn it: to strip VAT out of a gross price, divide by 1.2, not by 0.8. A £60 gross price is £50 net, not £48.
Crossing the threshold therefore cuts a consumer-facing business's revenue by 16.67% at unchanged prices. On £90,000 of sales that is £15,000 gone, partially offset by input VAT reclaims. You can model both sides in seconds with the UK VAT calculator.
Worked example: an IT consultant crossing the threshold
Priya is a self-employed IT consultant billing UK companies. Her rolling 12-month turnover hits £92,400 on 20 July. She must register by 30 August and is VAT-registered from 1 September.
She now expects £120,000 (excluding VAT) in her first full VAT year. Her clients are all VAT-registered, so she adds 20% and her day rate is unaffected in real terms.
- Net sales: £120,000
- VAT charged to clients at 20%: £24,000
- Gross invoiced (flat rate turnover): £144,000
- Purchases carrying VAT (software, accountant, laptop, phone): £6,000 net, so input VAT of £1,200
Standard VAT accounting: £24,000 output VAT minus £1,200 input VAT = £22,800 paid to HMRC. She keeps £120,000 net and has effectively saved £1,200 on her costs.
Flat Rate Scheme: "Computer and IT consultancy" carries a 14.5% rate. But Priya spends almost nothing on goods: software downloads, accountancy and phone bills are services, not goods. Her relevant goods are well under 2% of £144,000 (£2,880) and under £1,000, so she is a limited cost business and her rate is 16.5%.
- Year one (with the 1% new-registration discount, 15.5%): 15.5% x £144,000 = £22,320
- Year two onwards (16.5%): 16.5% x £144,000 = £23,760
So the Flat Rate Scheme saves her £480 in year one and then costs her £960 a year every year after that, on top of the fact that she cannot reclaim input VAT (capital assets over £2,000 aside). For her, standard accounting wins. Her income tax position is separate: use the sole trader tax calculator to see how the profit flows through to Income Tax and National Insurance.
The Flat Rate Scheme: when it helps and when it costs you money
Under the Flat Rate Scheme (FRS) you still charge customers 20%, but you pay HMRC a fixed percentage of your VAT-inclusive turnover and give up the right to reclaim input VAT on most purchases. You can join if your expected taxable turnover is £150,000 or less excluding VAT, and you must leave once total income including VAT exceeds £230,000 at your annual anniversary check.
| Business sector | Flat rate | Year-one rate (1% discount) |
|---|---|---|
| Retailing food, confectionery, newspapers | 4% | 3% |
| Retailing (not elsewhere listed) | 7.5% | 6.5% |
| General building or construction (labour and materials) | 9.5% | 8.5% |
| Transport or storage, including couriers | 10% | 9% |
| Advertising | 11% | 10% |
| Photography | 11% | 10% |
| Hairdressing or other beauty treatment | 13% | 12% |
| Accountancy or book-keeping | 14.5% | 13.5% |
| Computer and IT consultancy | 14.5% | 13.5% |
| Legal services | 14.5% | 13.5% |
| Limited cost business (any sector) | 16.5% | 15.5% |
Since the limited cost business rule was introduced, the FRS has stopped working for most consultants, contractors and other service businesses with no material purchases. At 16.5% of gross you are handing over 19.8% of your net sales, which is worse than 20% minus even a tiny amount of input VAT. Check the full sector list in HMRC's flat rate table before assuming your trade sector rate applies.
The FRS still earns its keep for businesses that buy few goods but sit on a low sector rate, and for anyone who values the admin saving: no purchase-by-purchase input VAT records, one percentage, one number.
Voluntary registration: who should do it early
You can register voluntarily at any turnover, even £0. It makes sense when:
- Your customers are VAT-registered. The 20% costs them nothing and you reclaim VAT on every cost. A B2B software freelancer with £8,000 of annual costs recovers around £1,333.
- You are zero-rated. Food producers, children's clothing sellers and publishers charge 0% but reclaim on everything: a permanent repayment position.
- You have heavy startup spend. Fit-out, plant and equipment carry recoverable VAT, and you can reclaim VAT on goods bought up to 4 years before registration (if you still hold them) and services bought in the previous 6 months.
- You want to look established. A VAT number signals a business over £90,000. Not a good reason on its own, but it is a real one for some buyers.
Do not register voluntarily if you sell to consumers and cannot raise prices. You would be donating one sixth of your revenue for the privilege of extra paperwork.
Deadlines, Making Tax Digital and the penalty regime
Almost all VAT-registered businesses file quarterly. The return and the payment are both due one calendar month and seven days after the period ends: for a quarter ending 31 March, that is 7 May.
Every VAT-registered business must comply with Making Tax Digital for VAT: digital records and returns filed through compatible software. Spreadsheets are allowed only with bridging software, and a manual keying-in on the HMRC portal is no longer an option.
Miss a return and you collect a penalty point. At four points (quarterly filers) you get a £200 penalty, and another £200 for every late return after that, per HMRC's points guidance. Miss a payment and you get nothing for 15 days, then 3% of the outstanding VAT at day 15, another 3% of what is still owed at day 30, and a second penalty accruing daily at 10% a year from day 31, on top of late payment interest. Agreeing a Time to Pay arrangement within 15 days stops the penalty clock.
Deregistering, and the trap of hovering under £90,000
You can ask HMRC to cancel your registration if your taxable turnover for the next 12 months will be below £88,000. The deregistration threshold is deliberately £2,000 lower than the registration one so that businesses trading right at the line are not registering and deregistering every year. You cannot deregister retrospectively just because turnover dropped, and you must be able to evidence the expected fall.
Watch the exit charge: on deregistration you owe VAT on stock and assets you still hold on which you reclaimed input VAT, if that VAT would come to more than £1,000.
Finally, resist the urge to cap your growth just below £90,000. Turning away work to stay under the threshold caps your profit permanently. The honest calculation is: what does 20% actually cost me given who my customers are, and can I recover part of it through input VAT and a modest price rise? Run the numbers on both sides with the VAT calculator before you decide the threshold is a wall rather than a step.