What to Do If You Accidentally Cross the VAT Threshold
Crossed the £90,000 UK VAT threshold by accident? Learn how to calculate your rolling turnover, registration deadlines, and how to apply to HMRC for a temporary exception.
If you accidentally cross the UK VAT threshold, you must take swift action to avoid penalties. You either need to register for VAT within 30 days of the end of the month in which you breached the limit, or apply immediately for a formal registration exception if the breach was only temporary.
Key Takeaways
- The UK VAT threshold is £90,000, calculated on a rolling 12-month basis.
- The deregistration limit is £88,000, which acts as the maximum target for temporary exception requests.
- You have 30 days to register after the end of the month of the breach to avoid late registration penalties.
- Temporary exception applications must be submitted using form VAT5EXC with strong supporting evidence of reduced future income.
- Late registration results in backdated VAT liabilities on all sales made since the date you should have been registered.
What is the UK VAT threshold, and how does the rolling limit work?
The UK VAT registration threshold is £90,000 of taxable turnover assessed on a continuous, rolling 12-month basis rather than a fixed tax or calendar year. Taxable turnover includes all standard-rated, reduced-rated, and zero-rated sales, but explicitly excludes any VAT-exempt transactions.
| Threshold Type | Limit Amount | Rule Application |
|---|---|---|
| Registration Threshold | £90,000 | Compulsory registration is triggered when your rolling 12-month taxable turnover exceeds this amount. |
| Deregistration Threshold | £88,000 | The level your future turnover must remain below to apply for a registration exception or to cancel your registration. |
How do you calculate exactly when you crossed the threshold?
To calculate exactly when you crossed the registration limit, you must evaluate your cumulative taxable sales at the close of every single calendar month. This is not a snapshot of your annual accounting year, but a continuous backward look over the previous 12 months.
- Identify your total taxable sales (excluding exempt transactions) for the last 12 months at the end of each calendar month.
- Pinpoint the exact calendar month where this running cumulative total first surpassed the £90,000 limit.
- Mark the final day of that specific calendar month to begin the 30-day countdown for your registration deadline.
What is my deadline to register for VAT after crossing the limit?
Your deadline to register is exactly 30 days from the end of the calendar month in which your cumulative rolling taxable turnover breached the £90,000 limit. The effective date of registration, which dictates when you must start accounting for VAT, depends entirely on whether the breach is historical or prospective.
| Breach Type | Scenario Details | Registration Deadline | Effective Date of Registration |
|---|---|---|---|
| Historical Breach | Turnover crossed £90,000 over the preceding 12 months. | Within 30 days of the end of the month of the breach. | First day of the second month following the breach month. |
| Prospective Breach | You expect turnover to cross £90,000 in the next 30 days alone. | By the end of that 30-day window. | The date you first realised the threshold would be breached. |
For example, if your cumulative rolling turnover first crossed £90,000 on 4 May 2026, your 30-day clock begins at the end of that month (31 May 2026). You must submit your registration to HM Revenue and Customs by 30 June 2026, and your official effective registration date will be 1 July 2026.
Can I apply for a VAT exemption if the breach was temporary?
You can apply for a formal exception from registration under Schedule 1 to the VAT Act 1994 if you can prove the threshold breach was temporary. This is not an automatic administrative opt-out, and it requires concrete proof that your business turnover will quickly drop below the deregistration limit.
- The breach of the £90,000 threshold must be a genuinely temporary, non-recurring event, such as a one-off contract or seasonal sales spike.
- You must demonstrate that your taxable turnover will remain below £88,000 for the next 12 months.
- The application must be based entirely on a historical breach; exceptions are never granted if you expect to exceed £90,000 in the next 30 days alone.
How do I apply for a VAT registration exception from HMRC?
To apply for a VAT registration exception, you must submit a formal request to HM Revenue and Customs explaining the temporary nature of your sales spike. You must supply convincing documentary evidence to support your claims.
- Complete the official HMRC form VAT5EXC or prepare a detailed written submission explaining the circumstances of the threshold breach.
- Gather robust documentary evidence, such as signed contracts showing a project has ended, future sales forecasts, or evidence of a non-recurring business asset sale.
- Submit the completed form and your evidence to HMRC before your 30-day registration deadline expires.
- Await HMRC's decision; if they reject your application, they will progress your VAT registration using your original compulsory date.
What happens if I registered late for VAT?
Registering late for VAT carries significant financial penalties, as you are legally required to account for VAT from your official backdated registration date. You must pay HM Revenue and Customs VAT on all taxable sales made since the date you should have been registered.
- Backdated Liabilities: You must pay VAT on all taxable transactions starting from your correct effective date of registration.
- Late Registration Penalties: HMRC can levy a penalty calculated as a percentage of the net VAT outstanding, which varies depending on how late the registration is and the nature of the disclosure.
- Voluntary Disclosure Benefits: Proactively reporting the delay to HMRC before they contact you usually results in significantly lower penalty percentages.
How to handle an accidental VAT breach: next steps
If you discover that your business has crossed the VAT threshold accidentally, acting quickly is vital to limit potential financial penalties and interest charges. Use this checklist to establish your position and coordinate your response.
- [ ] Calculate your exact rolling 12-month taxable turnover at the end of each month to confirm the precise date of the breach.
- [ ] Assess whether your future taxable turnover will consistently remain below £88,000 over the next 12 months.
- [ ] If you qualify for an exception, compile your future forecasts and contract end dates to submit form VAT5EXC.
- [ ] If you do not qualify for an exception, register for VAT using the online service immediately to stop late registration penalties from escalating.
- [ ] Consider consulting a professional tax advisor to ensure your exception application or late-registration disclosure is prepared correctly.
What is the penalty for late VAT registration?
The penalty is worked out as a percentage of the VAT you owe from the date you should have registered. This percentage depends on how late you are and whether HMRC had to contact you first or if you disclosed the error voluntarily.
Can I apply for a VAT registration exception retrospectively?
No. Once the registration deadline has passed and you have entered late registration territory, HMRC will not grant a retrospective exception. You must apply within the 30-day window following the month of the breach.
How does HMRC define a temporary breach of the VAT threshold?
HMRC defines a temporary breach as a short-term, non-recurring event where sales temporarily exceed £90,000, provided you can prove that your taxable turnover will drop and remain below £88,000 for the next 12 months.
Do exempt sales count towards the £90,000 UK VAT threshold?
No. Only standard-rated, reduced-rated, and zero-rated sales count towards the £90,000 threshold. Any income that is legally classified as VAT-exempt is excluded when calculating your rolling taxable turnover.