VAT registration: when you must register, when you should, and when you shouldn't
A factual guide to UK VAT registration. The £90,000 threshold, voluntary registration, flat rate scheme, and how to decide whether registering is right for your business.
VAT is the tax most UK business owners get wrong most often. Some register too early and needlessly load 20% onto their prices. Others register too late and get a backdated liability that wipes out months of profit. Others get stuck inside schemes that stopped serving them years ago.
This guide sets out the rules as they stand for 2026/27: when registration is compulsory, when it is voluntary but sensible, the main schemes available, and the specific situations where deregistering makes sense.
The compulsory registration rules
You must register for VAT if either of the following happens.
1. The historic test: taxable turnover exceeds £90,000 in the past 12 months
The £90,000 threshold applies to taxable turnover, which is all supplies that would be subject to VAT (at any rate, including zero) if you were already registered. It is not annual turnover in the accounting sense. It is a rolling 12-month figure checked every month.
Key points:
- The threshold is checked monthly, not at year end
- You must register within 30 days of the end of the month in which you exceeded £90,000
- Registration takes effect from the first day of the second month after you crossed the threshold
- The £90,000 applies to total taxable turnover, not to profit
Example: A consultant's rolling 12-month turnover reaches £92,000 on 15 March 2026. They must notify HMRC by 30 April 2026. Registration takes effect from 1 May 2026.
2. The future test: turnover will exceed £90,000 in the next 30 days alone
If you know at any point that your taxable turnover in the next 30 days alone will exceed £90,000, you must register immediately, from the start of that 30-day period. This catches one-off spikes: a single large contract, a major retail event, a corporate purchase order.
The deregistration threshold
You can ask HMRC to deregister when your rolling 12-month turnover drops below £88,000 and you expect it to stay there. This is a voluntary step. Deregistration is never automatic, and HMRC will check whether your expectation is reasonable.
Voluntary registration: when it is a good idea
You can register voluntarily at any time, even if your turnover is below £90,000. The question is whether you should.
When voluntary registration makes sense
Your customers are VAT-registered businesses. If you sell to other VAT-registered businesses, they reclaim the VAT you charge. Your effective price to them is the same, but you get to reclaim VAT on your own purchases. Pure upside.
You make a lot of zero-rated supplies. Zero-rated goods and services (children's clothes, most food, books, exports outside the UK) are taxable at 0%, which means you charge no VAT but can reclaim VAT on purchases. Voluntary registration turns you into a net reclaimer.
You want the credibility of being VAT-registered. Some corporate customers will not deal with unregistered suppliers. The VAT number on your invoice is a signal of legitimacy.
You are buying significant stock or equipment. Large VAT-inclusive purchases mean a chunky reclaim on your first return. If you are about to spend £20,000 on equipment, voluntary registration recovers £4,000 you would otherwise absorb.
When voluntary registration is a bad idea
Your customers are consumers or non-VAT-registered businesses. These customers cannot reclaim VAT. Registering means either raising your prices by 20% (losing customers) or absorbing the 20% yourself (losing 20% of your margin). Both are painful.
Your expenses are low. If most of your cost base is wages, rent without VAT, or services from non-VAT-registered suppliers, you have very little VAT to reclaim. The admin cost of VAT returns is not offset by meaningful recoveries.
You are genuinely small and staying small. VAT registration means quarterly returns, digital records under MTD for VAT, and ongoing compliance cost. If your business has no ambition beyond £50,000, registering voluntarily adds burden without benefit.
The schemes: standard, flat rate, cash accounting, annual accounting
Once registered, there are four schemes to be aware of.
Standard VAT accounting
The default. You charge VAT on sales, reclaim VAT on purchases, and pay the difference to HMRC quarterly. Records must be kept digitally under Making Tax Digital for VAT.
Flat Rate Scheme (FRS)
Designed for small businesses. You charge VAT at 20% as normal but pay HMRC a flat percentage of your gross turnover (including the VAT). You do not generally reclaim VAT on purchases.
Available to businesses with expected taxable turnover under £150,000 (excluding VAT) in the next 12 months. You must leave the scheme when turnover exceeds £230,000.
Flat rate percentages vary by industry. Consulting is 14.5%, IT services 14.5%, catering 12.5%, and so on. There is also a 1% discount in the first year of VAT registration.
The "limited cost business" trap. Since April 2017, businesses whose VAT-inclusive spending on goods is less than 2% of turnover (or less than £1,000 per year) are classified as limited cost businesses and must use a flat rate of 16.5%, regardless of their industry. At 16.5%, the FRS almost always produces a worse result than standard VAT accounting. This change effectively ended the FRS as a profit-generating tool for most service businesses.
Cash accounting scheme
Available to businesses with expected taxable turnover under £1.35 million. You account for VAT on the date you receive payment from customers, not the date of the invoice, and reclaim VAT only when you pay suppliers.
The main benefit is cash flow: you don't pay VAT to HMRC on invoices that have not yet been paid. The main drawback is that you cannot reclaim VAT on purchases until you have paid the supplier.
For businesses with slow-paying customers, cash accounting is often a better fit than standard accounting.
Annual accounting scheme
Available to businesses with expected turnover under £1.35 million. You file one VAT return a year and make monthly or quarterly payments on account. Useful for businesses that prefer a single annual compliance exercise to four quarterly returns.
Making Tax Digital for VAT
All VAT-registered businesses, regardless of turnover, must keep digital records and submit VAT returns via MTD-compatible software. This has been the rule since April 2022. There is no threshold exemption.
Compatible software includes Xero, QuickBooks, Sage, FreeAgent, and bridging software for spreadsheet users. Paper records and manual return submission are not compliant.
The most common mistakes
Not tracking the rolling 12-month turnover. Many businesses check their turnover at year end and miss the threshold by months. The penalty for late notification is based on how long you failed to register, and can be 5% to 15% of the VAT due during that period.
Assuming the threshold is £90,000 of profit. It is not. It is £90,000 of taxable turnover, which is nearly always a much larger number.
Choosing Flat Rate Scheme without running the maths. FRS is worse than standard accounting for most limited cost businesses. Always compare both under realistic assumptions before joining.
Forgetting to deregister when eligible. A business that drops below £88,000 permanently stays on the hook for quarterly returns until it actively deregisters.
Charging the wrong rate. Not everything is 20%. Food, books, children's clothes, and most exports are zero-rated. Domestic energy is 5%. Insurance, financial services, and health services are exempt (not the same as zero-rated). Getting the rate wrong is one of the most common reasons for VAT investigations.
The bottom line
Register when you must (£90,000 rolling 12-month taxable turnover). Register voluntarily only if your customers are VAT-registered or you have significant reclaimable VAT. Think twice before joining the Flat Rate Scheme if you are a limited cost business. Keep your records digital. And check your 12-month rolling turnover every month if you are anywhere near the threshold.
S&J handles VAT registration, scheme selection, and quarterly returns as part of every Insights and Foresight package. Pricing on the quote generator.