Most people know VAT registration has a turnover threshold. Fewer realise it's measured on a rolling 12-month basis rather than your tax year or the calendar year, which is where the trap usually is — a strong few months can tip you over without a single "annual" figure ever crossing the line.

The compulsory threshold

Registration becomes compulsory once your VAT-taxable turnover goes over £90,000 in any rolling 12-month period, not a fixed year. You need to register within 30 days of the end of the month in which you went over the threshold, and you become VAT-registered from the first day of the second month after that. Missing this window doesn't remove the liability — HMRC can register you anyway, backdated, which is a far less comfortable position than registering on time.

Registering voluntarily

You can register before you're required to, and there are good reasons some businesses do: it lets you reclaim VAT on costs and equipment, and in some cases it can be backdated to recover VAT on purchases made before registration, within limits. If most of your customers are other VAT-registered businesses, charging VAT usually makes little practical difference to them and can make your business look more established. The right call depends on who your customers are and what you're buying.

What changes once you're registered

You'll need to charge VAT on taxable sales, file returns (quarterly for most businesses) through Making Tax Digital-compatible software, and keep digital records of your VAT transactions. You also have a choice of VAT schemes, each suited to different kinds of business, which is worth getting advice on rather than defaulting to the first option you see.

VAT schemes: flat rate, cash accounting and annual accounting

The standard way to account for VAT is to charge VAT on your sales, reclaim the VAT on your costs and pay HMRC the difference. Three optional schemes change how or when you do that. Each has turnover limits for joining and for leaving.

Flat Rate Scheme. You pay HMRC a fixed percentage of your VAT-inclusive turnover, with the percentage set by your type of business, and you generally don't reclaim VAT on your purchases, apart from certain capital assets over £2,000. You can join if you expect VAT-taxable turnover of £150,000 or less, excluding VAT, over the next 12 months, and you must leave if your turnover goes above £230,000 including VAT. There is a 1% reduction in the rate for your first year as a VAT-registered business. If you spend very little on goods, a higher fixed rate of 16.5% applies. It can save paperwork, but whether it saves money depends on how much VAT you would otherwise reclaim.

Cash Accounting Scheme. Under the VAT Cash Accounting Scheme, you generally account for VAT on your sales when your customers pay you, rather than when you issue invoices. You also normally reclaim VAT on purchases when you pay your suppliers. Some transactions are excluded from the scheme. That helps if customers are slow to pay. You can join if your VAT-taxable turnover is expected to be £1.35 million or less over the next 12 months, and you must leave if it goes above £1.6 million.

Annual Accounting Scheme. You file one VAT return a year instead of four, and make regular payments towards your bill through the year, based on your previous year's VAT. The same turnover limits apply as for cash accounting: £1.35 million to join, and you must leave above £1.6 million. It suits a business with steady figures that would rather file once a year, but you still need up-to-date records to know where you stand.

These limits are set by HMRC and can change, and the right scheme depends on your costs, how quickly customers pay and how you like to manage cash. We check the figures for you before recommending one.

What if I go over the threshold temporarily?

If a one-off spike pushes you over £90,000 but you genuinely expect to be back below £88,000 within the next 12 months, you can apply to HMRC for a registration exception rather than registering. This needs evidence to support the expectation, not just a hope — it's worth talking it through before assuming you qualify.

What happens if I register late?

HMRC can charge a penalty based on how late the registration is and how much VAT was due in the meantime. If you think you may already be over the threshold, the right move is to establish the position and register promptly rather than wait — early, voluntary correction is treated far more favourably than being caught out later.

Not sure whether you need to register?

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