If you crossed the £90,000 threshold and told HMRC late, the VAT late registration penalty is a percentage of the net VAT that went unpaid during the delay. That percentage runs from 0% for a careless slip you disclose voluntarily up to 100% where the failure was deliberate and concealed. You also owe the underlying VAT itself, plus late payment interest, and HMRC has up to 20 years to come after both.
How the Penalty Amount Is Calculated
The percentage is applied to something HMRC calls Potential Lost Revenue, or PLR: the net VAT that should have been paid between the date registration should have taken effect and the date you actually notified HMRC. The statutory framework sits in Schedule 41 of the Finance Act 2008.1The National Archives. Finance Act 2008, Schedule 41
PLR is not just the output VAT on your sales during the missing period. HMRC lets you treat as input tax the VAT you paid on stock and assets still held at the effective date of registration, and on business services received in the six months before that date. Netting these off often shrinks the PLR sharply, and shrinks the penalty with it.2GOV.UK. Compliance Handbook CH72740 – Calculating the Penalty: Potential Lost Revenue: VAT Registration
A business making only zero-rated supplies has no output VAT to lose. PLR is nil, and the penalty percentage has nothing to bite on. The percentage still gets set on paper, but the cash penalty is zero.
Penalty Rates by Behaviour and Disclosure
HMRC sorts every failure to notify into one of three behaviour categories, and each category has two rate ranges: one if you came forward before HMRC started asking questions (unprompted), and a stiffer one if you only owned up after HMRC began looking (prompted).3GOV.UK. Compliance Checks: Penalties for Failure to Notify – CC/FS11
Non-Deliberate
A genuine oversight, such as not spotting that your rolling turnover had crept past the threshold.
- Unprompted, within 12 months of the tax being due: 0% to 30% of PLR
- Unprompted, more than 12 months after the tax was due: 10% to 30%
- Prompted, within 12 months: 10% to 30%
- Prompted, more than 12 months after: 20% to 30%
Spot the problem yourself, act quickly, and the penalty can be reduced to nothing.
Deliberate
You knew the threshold had been crossed and chose not to register.
- Unprompted: 20% to 70%
- Prompted: 35% to 70%
Deliberate and Concealed
You knew, and you took active steps to hide it, such as running two sets of books or routing sales through a separate entity.
- Unprompted: 30% to 100%
- Prompted: 50% to 100%
Moving Down Within the Band
Where you land inside the applicable range depends on how you cooperate on three fronts: telling, helping, and giving access.4GOV.UK. Compliance Handbook CH82460 – Penalties for Failure to Notify
Telling means explaining what went wrong, when, and why. Helping means working with HMRC to quantify the tax that was lost, including pulling records and doing calculations. Giving access means opening your business records, documents, and premises without forcing HMRC to reach for formal information powers. Prompt, voluntary handover earns a bigger reduction than material produced only after repeated requests. HMRC also expects you to offer relevant records they haven’t specifically named; holding anything back, even by accident, trims the credit.
In genuinely exceptional cases HMRC can apply a “special reduction” that drops the penalty below the normal minimum for your category. The power is discretionary and rarely used. Failure-to-notify penalties cannot be suspended, unlike some other VAT penalties.
Interest and the 20-Year Window
The penalty is not the whole bill. HMRC charges late payment interest on any unpaid VAT from the first day the payment was overdue until it clears.5GOV.UK. Late Payment Interest if You Do Not Pay VAT or Penalties on Time
And the clock is long. Most VAT assessments have a four-year time limit, but for a failure to notify the registration obligation HMRC has 20 years to assess the tax and penalty. Sitting quietly and hoping the issue ages out is not a strategy.6GOV.UK. Compliance Handbook CH53900 – Assessing Time Limits: Extended Time Limits: Failure to Notify or Register
Appealing the Penalty
You have 30 days from the date on the penalty notice to challenge it.7GOV.UK. Disagree with a Tax Decision or Penalty
Start with a statutory review. An HMRC officer who had no hand in the original decision looks again at the facts and any evidence you supply. The review is free and can cut or cancel the penalty.
If the review does not resolve things, the next step is the First-tier Tribunal (Tax Chamber). Appeals there frequently turn on whether you had a reasonable excuse for the late notification.
What Counts as a Reasonable Excuse
A reasonable excuse is something that genuinely stopped you meeting the obligation on time. HMRC’s published examples include:8GOV.UK. Disagree with a Tax Decision or Penalty: Reasonable Excuses
- A serious or life-threatening illness, or an unexpected hospital stay
- The death of a partner or close relative shortly before the deadline
- A fire, flood, or theft that prevented you from dealing with your tax affairs
- Computer or software failure while preparing your return
- Problems with HMRC’s own online services
- Being unaware of or genuinely misunderstanding your legal obligation
- Relying on someone else, such as an accountant, who failed to handle the registration
Some arguments will not work. Shortage of money, finding HMRC’s systems awkward, not getting a reminder, or making a calculation error are all excluded. And whatever the excuse, you must have acted as soon as it stopped applying. An excuse that covered six months ago does not cover the five months of inaction after it fell away.
If You Miss the 30-Day Deadline
Missing the window does not close the door permanently. You can apply to HMRC or the tribunal for a late appeal, but you have to explain the delay, and the case gets harder the longer you leave it. Acting inside the 30 days is always the safer route.
If the Breach Was a One-Off
One boundary worth flagging. If your turnover crossed £90,000 but you can show it will not exceed the £88,000 deregistration threshold in the next 12 months, you can apply for an exception from registration using forms VAT1 and VAT5EXC. HMRC responds within 40 working days.9GOV.UK. Apply for an Exception from Registering for VAT An exception application does not pause or cancel any penalty that has already been assessed for a period of late notification; it addresses whether you have to register going forward, not what you owe for the time you were late.