Plenty of sole traders treat the VAT threshold like a speed limit: stay under £90,000 and you are fine, cross it and you are in trouble. That is the wrong way to read it. For some businesses, registering for VAT a year before they legally have to is the smartest money move they make all year. For others, hitting the threshold means handing roughly a sixth of their turnover to the customer's price tag, with nothing obvious to claw back. The number itself tells you very little. What matters is who your customers are and how much you spend on things that carry VAT.
The compulsory registration threshold has sat at £90,000 of VAT-taxable turnover since April 2024, and it stays there for the 2026/27 tax year. The deregistration threshold is £88,000. Both figures are measured on a rolling 12-month basis, not your accounting year or the tax year — and that rolling test is exactly where people get caught out.
The rolling 12-month test, and the trap inside it
HMRC does not wait for your year-end. You must register if your VAT-taxable turnover over any rolling 12-month period goes above £90,000, or if you expect to cross it within the next 30 days alone. The first test looks backwards every single month; the second looks forwards at a single large contract. A landscaper who signs one £95,000 commercial job becomes liable under the 30-day rule before the rolling figure ever moves.
Miss the deadline and the penalty is not just the VAT you should have charged. You become liable for the VAT on everything you sold after the date you should have registered — whether or not you actually collected it from customers. A decorator who drifts £4,000 over the line and notices six months later can find themselves owing HMRC the VAT on half a year of invoices out of their own pocket, because going back to a long list of householders to ask for an extra 20% is, in practice, impossible. That is the real cost of treating the threshold as a year-end number rather than a monthly one.
There is one genuine relief worth knowing. If you breach the threshold temporarily and can show HMRC your turnover for the next 12 months will stay under £88,000, you can apply for an exception to registration. It is granted case by case, you have to ask before the deadline passes, and HMRC will want evidence — a lost contract, a one-off spike — rather than optimism.
Voluntary registration: the move most people get backwards
You can register for VAT at any turnover, even from your first invoice. Whether you should comes down to one question: do your customers pay VAT themselves?
If you mostly sell to other VAT-registered businesses, voluntary registration is usually the better choice, and the reasoning is simple. Your business customers reclaim the VAT you charge them, so your prices do not effectively rise for them. Meanwhile you start reclaiming the VAT on everything you buy — laptops, software subscriptions, fuel, tools, an accountant's fees. A freelance developer turning over £45,000 who spends £8,000 a year on a new MacBook, Adobe subscriptions and a co-working desk is leaving around £1,300 of reclaimable VAT on the table by staying unregistered. Register, and that £1,300 comes back.
The picture flips entirely if your customers are the public. A mobile hairdresser or a dog groomer selling to households gains nothing from reclaiming a few hundred pounds of input VAT if registration forces them to either raise prices 20% or absorb the hit on their margin. For consumer-facing microbusinesses, staying under the line as long as legally possible is almost always right. There is a third, quieter reason firms register early, and it is reputational: some larger clients will not place work with a supplier whose lack of a VAT number signals a turnover under £90,000. Looking established is occasionally worth more than the arithmetic.
The Flat Rate Scheme: simpler, sometimes cheaper, often misjudged
Once registered, you do not have to track input and output VAT line by line. The Flat Rate Scheme lets businesses with VAT-taxable turnover up to £150,000 (excluding VAT) pay a fixed percentage of their gross, VAT-inclusive turnover to HMRC and keep the difference. The percentage depends on your trade — a management consultant pays 14%, a hairdresser 13%, a clerical or business-services firm 12%, while many trades sit between 9.5% and 14.5%.
The catch arrived in 2017 and still trips people up: the limited cost trader rule. If you spend less than 2% of your turnover (or less than £1,000 a year) on physical goods, you are forced onto a 16.5% flat rate regardless of your trade — which on the maths leaves almost nothing in your pocket. The scheme was designed for businesses that buy little; the limited cost trader rule was added precisely because too many service firms were profiting from it. Run the numbers before you opt in, not after.
Here is the honest verdict. The Flat Rate Scheme is genuinely worth it for two kinds of business: those whose flat percentage is comfortably below what they would pay under standard VAT accounting, and those who simply value never having to file a detailed input-VAT calculation again. For anyone with significant VATable costs — a trade buying materials, a retailer buying stock — standard accounting almost always wins, because under the flat rate you generally cannot reclaim VAT on purchases at all. The one standing exception: you can still reclaim VAT on a single capital asset costing £2,000 or more including VAT, so a one-off van or a serious piece of kit is recoverable even on the scheme.
Making Tax Digital is no longer optional, and the rules tightened
Every VAT-registered business, regardless of turnover, must now follow Making Tax Digital for VAT. That means keeping digital records and filing returns through HMRC-recognised software — the days of typing nine boxes into the HMRC website by hand are over. The old voluntary-registration exemption that let smaller firms sidestep MTD was removed back in April 2022, so if you register today, MTD applies from your very first return.
In practice this means a subscription to something like Xero, QuickBooks or FreeAgent, or at minimum bridging software that pulls figures from a spreadsheet into HMRC's system. HMRC is explicit that copy-and-paste between programs breaks the rules: there must be a digital link — an unbroken digital trail — from your records to your submitted return. A spreadsheet is still allowed as your bookkeeping record, but it has to connect to filing software through a recognised bridge, not a manual retype.
The penalty regime changed too, and it is worth understanding before your first deadline. Late VAT returns now run on a points system: you collect a point for each late submission, and once you hit the threshold for your filing frequency — four points for quarterly filers — a £200 penalty lands, with a further £200 for every late return after that. Late payment is charged separately and rises the longer the debt sits. The system is more forgiving of a single slip than the old regime and far less forgiving of a habit.
The decision, stripped down
If you sell to businesses and you are anywhere near £90,000, register — ideally before you have to, so you start reclaiming input VAT and stop worrying about the rolling test. If you sell to the public, stay under the line for as long as the law allows, and the day you cross it, price the VAT in deliberately rather than letting it eat your margin. Check the Flat Rate Scheme maths against your real costs before opting in, and never assume the headline percentage is the one you will actually pay. And whichever route you take, set up MTD-compliant software the same week you register — not the week your first return is due, when HMRC's clock is already running.