William J Cook v The Commissioners for HMRC

Decision date: 2 July 2026

Neutral citation: [2026] UKFTT 998 (TC)

Overall AI summary confidence: high

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Short overview

This short overview is intended to summarise the case, issues and outcome so far as they are supported by the judgment.

AI confidence in this short overview: high

This case concerns William J Cook’s application for permission to bring late appeals against HMRC assessments and penalties for 2009–10 to 2019–20 arising from a COP9 investigation. Applying the established three-stage Martland/Denton approach, the Tribunal found the nearly two-year delays were serious, the Appellant did not establish a good reason for the delay (adviser failings were attributed to him), and refused permission to appeal out of time. HMRC’s supplementary witness evidence was admitted (with one email excluded). The Tribunal allowed the parties opportunity to seek permission to appeal its decision.

Ratio decidendi

This summary is intended to identify the ratio decidendi, meaning the legal reasons for deciding and the binding part of the decision.

AI confidence in this ratio decidendi summary: medium

The decision applies the three-stage approach to s49 TMA late-appeal applications: (1) assess the length of the delay, (2) consider the reasons for default, and (3) evaluate all the circumstances (including prejudice and finality). Contemporaneous documentary evidence is given primary weight where memory is weak, and ordinarily failures by a taxpayer’s advisers will be treated as the taxpayer’s failures and will not constitute a “good reason” for missing statutory appeal deadlines absent exceptional, well-evidenced circumstances.

Obiter dicta

This summary is intended to identify obiter dicta, meaning observations made by the way that were not necessary to deciding the case and are not binding.

AI confidence in this obiter dicta summary: medium

The Tribunal commented (obiter) that ignorance of the law or inexperience as a litigant is not a good reason for non-compliance, reliance on a non-expert bookkeeper known not to be a tax adviser does not absolve the taxpayer, and the threat or initiation of bankruptcy proceedings may prompt action but does not by itself justify earlier inaction.