VAT registration applies the same way regardless of whether you’re a sole trader or a limited company — it’s based on your turnover, not your business structure. But it’s often one of the more confusing parts of growing a business, because it changes how you price, invoice, and file, all at once.
The mandatory threshold
You must register for VAT once your VAT-taxable turnover exceeds the current registration threshold — £90,000 — in any rolling 12-month period — not a fixed tax year, but a rolling window that you need to keep an eye on continuously. You must also register if you expect to go over the threshold in the next 30 days alone. (This figure is set by HMRC and can change at the Budget, so it’s worth double-checking on GOV.UK if it’s been a while since you last looked.)
Once you’re over the threshold, you have 30 days to register, and you become liable for VAT from the point you should have registered — not just from when you actually do. This makes tracking turnover on a rolling basis genuinely important rather than a formality.
Example: A sole trader whose turnover crosses the threshold partway through March needs to register within 30 days of that point — not wait until the end of the tax year in April.
Voluntary registration below the threshold
You can register for VAT even if you’re well under the threshold. This isn’t common for very small businesses, but it makes sense in specific situations:
- You mostly sell to VAT-registered businesses — they can reclaim the VAT you charge, so it costs them nothing, and you get to reclaim VAT on your own purchases
- You have significant upfront costs — equipment, stock, or setup expenses with VAT on them that you’d like to reclaim
- You want to look more established — a VAT number can signal a certain scale to clients or suppliers, rightly or wrongly
- You must charge VAT on applicable sales (usually at the standard rate, though some goods and services have reduced or zero rates)
- You can reclaim VAT on eligible business purchases
- You must file VAT returns, usually quarterly, showing VAT charged and VAT reclaimed
- You need compliant digital record-keeping under Making Tax Digital rules
- Your prices to non-VAT-registered customers effectively increase, unless you absorb the VAT into your margin
Example (sole trader): A freelance IT consultant working exclusively for VAT-registered agencies might register voluntarily early on, since the agencies can reclaim the VAT charged and the consultant benefits from reclaiming VAT on a new laptop and software subscriptions.
Example (limited company): A new company selling to the public rather than other businesses would think twice before registering voluntarily, since the VAT charged simply increases the price the end customer pays, with no one to reclaim it back.
What changes once you’re registered
Registering for VAT isn’t just a form to fill in — it changes how the business runs:
Example: A tradesperson who registers for VAT and continues charging domestic customers the same headline price is effectively taking a 20% hit on that portion of income, since VAT now has to come out of what they charge rather than being added on top.
Deregistering
If turnover drops below the deregistration threshold — currently £88,000 — (set lower than the registration threshold, to avoid people flipping in and out), you can apply to deregister. This isn’t automatic — you have to request it, and there are some situations where staying registered still makes sense even if turnover has dipped.
The pricing decision that catches people out
The most common mistake isn’t failing to register — it’s not adjusting pricing early enough. If a business is close to the threshold and hasn’t decided how it will handle the transition, VAT registration can arrive as a shock to margins rather than a planned step.
Example: A business consistently priced at just under the threshold, growing steadily, benefits from deciding in advance whether prices will rise by the VAT amount or whether the business will absorb it — rather than making that call reactively in the same week registration becomes mandatory.
The short version
Whether you’re a sole trader or a limited company, the rules are identical — VAT tracks the business’s turnover, not its legal structure. The decision that matters is less “am I required to register” and more “does registering, mandatory or voluntary, work in my favour given who I sell to.”