You must register for VAT when your business’s taxable turnover passes £90,000 over any rolling 12-month period, or the moment you expect to pass £90,000 within the next 30 days alone.1GOV.UK. Register for VAT Whichever trigger hits first sets the clock, and knowing when to register for VAT means checking both every month rather than waiting for your year-end accounts. You can also register voluntarily below the threshold, and in some cases that pays off.
What Counts Toward the £90,000 Threshold
Taxable turnover is the total value of everything you sell or supply that is not exempt from VAT.2GOV.UK. How VAT Works – VAT Thresholds It is your gross sales figure before you subtract costs, wages, or overheads. Both standard-rated sales (charged at 20%) and zero-rated sales count. Zero-rated goods carry a VAT rate of 0%, but they are still taxable supplies for threshold purposes. Common zero-rated items include most food and drink for human consumption, though not confectionery, alcohol, or hot takeaways,3GOV.UK. VAT Rates on Different Goods and Services and young children’s clothing and footwear.4GOV.UK. Young Children’s Clothing and Footwear (VAT Notice 714)
Exempt supplies sit outside the VAT system entirely and do not count toward the threshold. Insurance and most financial services are the standard examples. The difference matters. A business selling £60,000 of standard-rated goods and £35,000 of zero-rated food has a taxable turnover of £95,000 and must register. A business earning £95,000 entirely from exempt financial services has no registration obligation at all.
The Rolling 12-Month Test
At the end of each month, add up your taxable turnover for the previous 12 months. If that rolling total exceeds £90,000, you have crossed the threshold. You must notify HMRC within 30 days of the end of the month you went over, and your effective date of registration is the first day of the second month after you crossed it.1GOV.UK. Register for VAT
Say your rolling 12-month turnover passes £90,000 at the end of July. You have until the end of August to notify HMRC. Your effective registration date is 1 September, and you must charge VAT on all taxable sales from that date. This is the trigger that catches most businesses, because the rolling window means checking every month, not just at year-end. A single strong month can tip you over, and if you spot it late, the tax owed still runs from that 1 September start date.
The 30-Day Expectation Test
The second trigger is less common but sharper. If at any point you expect your taxable turnover to exceed £90,000 within the next 30 days alone, you must register by the end of that 30-day period. Your effective registration date is the day you first formed that expectation, not the day the sales actually land.1GOV.UK. Register for VAT
This test usually bites when a business signs a large contract or takes a substantial order that will push turnover past the threshold in one go. If you land a £100,000 project on 10 March and expect to invoice it inside the month, your effective registration date is 10 March and you must notify HMRC by 9 April. VAT should be on your invoices from day one of that work.
When You Can Register Voluntarily Below the Threshold
Any business making taxable supplies can register voluntarily, even if turnover is well below £90,000.5HM Revenue & Customs. Increasing the VAT Registration Threshold The main reason is input tax recovery. Once registered, you can reclaim the VAT you pay on business purchases such as equipment, materials, software, and professional services.6GOV.UK. Charge, Reclaim and Record VAT If you regularly spend more on VAT-bearing costs than you collect from customers, registration can produce a net refund each quarter.
Voluntary registration also tends to suit businesses that sell mainly to other VAT-registered companies. Those customers reclaim any VAT you charge them, so the cost passes through, while you get to recover your own input tax. Some unregistered businesses lose B2B contracts because buyers prefer registered suppliers.
The tradeoff is administrative. You take on quarterly filing, digital record-keeping, and the responsibility of charging the right VAT on every sale. If you sell mainly to consumers, adding 20% to your prices can hurt when turnover is still low.
When You Can Ask Not to Register
If your taxable turnover passes £90,000 but most or all of your sales are zero-rated, you can apply for an exemption from registration.7GOV.UK. Register for VAT – Exemption from Registration The logic is that a business selling only zero-rated goods would owe no VAT on its output but would still be spending time filing returns. You request the exemption by specifying it on the VAT1 registration form, online or by post.
HMRC grants it if satisfied you would regularly receive refunds rather than owe tax. If your product mix later shifts toward standard-rated sales, you have to revisit your status. Food producers, publishers, and children’s clothing sellers commonly cross £90,000 without ever owing VAT, and this exemption is the reason.
What Happens If You Register Late
Missing the deadline costs you twice. HMRC backdates your registration to the date it should have started, so you owe the VAT you should have been charging across that whole period. You never collected it from your customers, so it comes out of your own margins.
On top of that, HMRC applies a failure-to-notify penalty. The old fixed-scale penalty was replaced in April 2010.8GOV.UK. Late VAT Registration Penalty (VAT Notice 700/41) The current regime is based on behaviour. Careless failures carry a maximum penalty of 30% of the potential lost revenue, deliberate failures up to 70%, and deliberate concealment up to 100%. Those maximums can be reduced if you tell HMRC about the error before they find it and if you cooperate fully with any enquiry. For a business that traded above the threshold for several months without noticing, the combined backdated tax and percentage penalty is the realistic danger.
How to Notify HMRC
Most businesses register online through the GOV.UK portal. You will need your Unique Taxpayer Reference, the 10-digit number issued when you registered for Self Assessment or set up a limited company,9GOV.UK. Find Your UTR Number your National Insurance number, your business bank account details, and your taxable turnover figures for the past 12 months. If you cannot register online, you can request a paper VAT1 form from HMRC and submit it by post.1GOV.UK. Register for VAT
The form covers the nature of your business, your expected turnover for the coming year, and any previous VAT registrations. Have your accounting records open before you start, because the online session can time out while you hunt for numbers. HMRC then issues a VAT registration certificate with your VAT number and your effective date of registration, and from that date you charge VAT on your taxable sales.