How to Dispute a Tax Decision or Complaint About HMRC

HMRC tax disputes: incorrect assessments, penalty appeals, tax code errors. HMRC complaints, ADR and Tax Tribunal routes.

If you disagree with a tax decision by HMRC — whether it is an assessment, penalty, or tax code — you can challenge it. For most decisions, you have 30 days to request a review or appeal to the First-tier Tribunal (Tax Chamber).

For service complaints (delays, errors, poor communication), use HMRC's formal complaints process. If HMRC does not resolve your complaint, escalate to the Adjudicator's Office — an independent body that investigates complaints about HMRC and the Valuation Office Agency.

HMRC also offers Alternative Dispute Resolution (ADR) for disputes about the amount of tax owed. ADR uses a trained HMRC facilitator (not the original caseworker) to help reach agreement without going to tribunal.

Key Legislation

  • Taxes Management Act 1970
  • Finance Act 2009
  • Taxpayers' Charter

Key Deadlines

  • Tax decision appeal: 30 days
  • HMRC complaint: no fixed deadline
  • Adjudicator: within 6 months of HMRC final response

Complaint Route

HMRC Complaints / Adjudicator's Office / Tax Tribunal

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