
August 21st, 2026
HMRC Appeal - Assessment Challenge
Tax Disputes | Appeals
A taxpayer received an assessment from HMRC that significantly overstated their liability.
HMRC had concluded an enquiry by issuing a closure notice with substantial amendments to the taxpayer's self-assessment, together with interest and penalties.
The taxpayer was adamant that HMRC's position was wrong and wished to challenge it.
The formal appeal process under UK tax law provides taxpayers with the right to challenge HMRC decisions. An appeal must be made within 30 days of the decision, and the taxpayer can then seek a statutory review by HMRC or proceed directly to the First-tier Tribunal.
We advised the taxpayer to appeal within the time limit to preserve their rights, while simultaneously engaging with HMRC to try to resolve the dispute without tribunal proceedings if possible.
Our notice of appeal set out the grounds on which the assessment was challenged:
Legal Grounds: We argued that HMRC had misinterpreted the relevant statutory provisions. We set out the correct interpretation, supported by case law and HMRC's own published guidance, and explained why the assessment did not accord with the law.
Factual Grounds: We challenged HMRC's findings of fact, pointing to documentary evidence that contradicted their conclusions. We argued that HMRC had made assumptions that were not supported by the evidence.
Computational Grounds: We identified errors in HMRC's calculations, demonstrating that even on their own interpretation of the law and facts, the assessment was arithmetically wrong.
Penalty Challenge: We argued that the penalty was unjustified because the taxpayer had taken reasonable care and had a reasonable excuse. We also challenged the quantum of the penalty.
Following the appeal, we requested a statutory review by HMRC. The review is conducted by an officer who was not involved in the original decision, providing a fresh pair of eyes. We submitted a detailed written submission to support the review.
We also engaged in without prejudice discussions with HMRC to explore whether a negotiated settlement was possible.
In tax disputes, early resolution often produces better outcomes than prolonged litigation, and we advised our client on the advantages and disadvantages of settlement versus proceeding to tribunal.
Outcome
Formal appeal lodged and statutory review requested.
Detailed grounds of appeal submitted challenging HMRC's legal interpretation, factual findings, computations, and penalty assessment.
Matter resolved in favour of the client after HMRC withdrew from appeal to tribunal.
This case study is based on a real client matter. All identifying details have been removed or changed to protect client confidentiality.