How to Dispute a VAT Assessment from HMRC

Challenge inaccurate VAT bills and protect your business interests

Quick Answer

You have 30 days from the assessment date to appeal a VAT assessment. Send a written notice of appeal to HMRC with supporting evidence (invoices, records, calculations). If HMRC rejects your appeal, you can request a review or appeal to the VAT Tribunal. Act fast—the 30-day deadline is strictly enforced.

Types of VAT Assessments You Can Dispute

HMRC issues VAT assessments when it believes you've underpaid VAT or overclaimed input tax. Assessments can cover single accounting periods or multiple years. If HMRC discovers you deliberately withheld information, assessments can include penalties (20–100% of unpaid VAT) and interest. You have the right to challenge any assessment if you believe it is incorrect.

Common grounds for dispute: HMRC misinterpreted records, you provided information HMRC failed to consider, or the assessment covers periods outside HMRC's legal time limit (4 years for careless errors, 20 years for deliberate concealment).

How to Appeal a VAT Assessment

Step 1: Act within 30 days. Count from the date on the assessment letter, not the date you received it. Send a formal notice of appeal to the HMRC office named on the letter. Keep a copy and send by recorded delivery.

Step 2: Build your case. Gather invoices, records, bank statements, and any correspondence with HMRC. Calculate exactly where HMRC went wrong. A clear, numbered response is far more persuasive than a rambling complaint.

Step 3: Request HMRC's review. If HMRC upholds the assessment after your appeal, request an independent review (different officer). If that fails, you have 30 days to appeal to the VAT Tribunal.

Step 4: Escalate to tribunal if necessary. The First-tier Tribunal (Tax Chamber) will hear both sides and make a binding decision. You can represent yourself or hire a tax advisor.

What the Law Says
Value Added Tax Act 1994, Chapter 2
Covers VAT assessments and disputes. You have a statutory right to appeal within 30 days of assessment notice. HMRC must show it followed proper procedure.
Finance Act 2008, Schedule 41
Defines penalties for VAT evasion and careless errors. Penalties range from 20% (careless) to 100% (deliberate concealment). You can challenge the penalty separately from the assessment.
Tribunal Procedure Rules 2009, Part 2
Sets out appeal procedures to the First-tier Tribunal. You must appeal within 30 days or provide a good reason for the delay. Tribunal decisions are binding.
What if I missed the 30-day deadline? +

The deadline is strictly enforced, but you can apply for late appeal if you have a good reason (illness, administrative error, reliance on professional advice). Explain clearly why you were late. HMRC will consider your application, but approval is not guaranteed.

Can I appeal a penalty separately from the VAT itself? +

Yes. You can dispute the VAT assessment and the penalty independently. For example, you may accept the VAT is due but argue the penalty is unfair because you acted without deliberate intent or relied on advice.

What records do I need to challenge an assessment? +

Invoices (in and out), bank statements, cash books, VAT returns you filed, professional correspondence, and anything showing HMRC's error. If records are lost, explain when and why. Contemporaneous notes (even rough ones) are valuable evidence.

Does HMRC have a time limit for assessing back years? +

Yes. HMRC can assess the last 4 years (careless errors) or 20 years (deliberate evasion). If the assessment covers periods older than this, challenge it as time-barred. This is often a strong defence.

Can I pay the VAT and appeal later? +

You can (and often should) pay the undisputed VAT to stop interest accruing while you appeal the amount. This is called "payment in the form of dispute." Confirm with HMRC that they understand this arrangement.

Dispute Your VAT Assessment