Zzaman v. HMRC
First-tier Tribunal (Tax Chamber) · Apr 3, 2025
What happened in this matter?
The Tribunal dismissed the appellant's tax appeal, finding his arguments lacked legal merit. It explicitly addressed the appellant's use of AI, noting that while the tool did not generate fictitious cases in this instance, it provided irrelevant or misapplied authorities that failed to support the appellant's claims, leading to a warning regarding the necessity of human verification for AI-generated legal research.
- Why the court cared
- The Tribunal reasoned that the appellant's arguments were unsupported by the cited case law, which was either irrelevant, tangential, or mischaracterized. It concluded that the discovery assessment was validly issued under the relevant tax statutes and that the appellant's reliance on AI without human verification resulted in the submission of material that did not assist the court.
- Why it matters now
- Even accurate case names can be misapplied by AI—verify that cited authority actually supports your proposition.
Why this matter is tracked
Fabricated: Case Law | Verify the existence of the case or cite correctly if it exists. Outcome: Warning. Plaintiff had disclosed the use of AI in preparing his statement of case. The court noted:"29. However, our conclusion was that Mr Zzaman’s statement of case, written with the assistance of AI, did not provide grounds for allowing his appeal. Although some of the case citations in Mr Zzaman’s statement were inaccurate, the use of AI did not appear to have led to the citing of fictitious cases (in contrast to what had happened in Felicity Harber v HMRC [2023] UKFTT 1007 (TC)). But our conclusion was that the cases cited did not provide authority for the propositions that were advanced. This highlights the dangers of reliance on AI tools without human checks to confirm that assertions the tool is generating are accurate.Litigants using AI tools for legal research would be well advised to check carefully what it produces and any authorities that are referenced. These tools may not have access to the authorities required to produce an accurate answer, may not fully “understand” what is being asked or may miss relevant materials. When this happens, AI tools may produce an answer that seems plausible, but which is not accurate. These tools may create fake authorities (as seemed to be the case in Harber) or use the names of cases to which it does have access but which are not relevant to the answer being sought (as was the case in this appeal).There is no reliable way to stop this, but the dangers can be reduced by the use of clear prompts, asking the tool to cite specific paragraphs of authorities (so that it is easy to check if the paragraphs support the argument advanced), checking to see the tool has access to live internet data, asking the tool not to provide an answer if it is not sure and asking the tool for information on the shortcomings of the case being advanced. Otherwise there is a significant danger that the use of an AI tool may lead to material being put before the court that serves no one well, since it raises the expectations of litigants and wastes the court’s time and that of opposing parties."
Even accurate case names can be misapplied by AI—verify that cited authority actually supports your proposition.
Record details
What the record establishes about AI use
The appellant confirmed using AI to prepare his statement of case.
Appeal to the First-tier Tribunal (Tax Chamber) against a discovery assessment for HICBC; appeal dismissed.
Correction behavior is not separately verified in the current record.
Tracked discrepancy record
11 citation, quotation, or authority issues are recorded in the source dataset.
- Fabricated: Case Law | Verify the existence of the case or cite correctly if it exists.
- Misrepresented: Case Law | Unilever Italia (ECJ, C-443/98) was invoked as relevant to retrospective tax fairness; the Tribunal found it concerned national technical regulations and was irrelevant.
- Misrepresented: Case Law | R v R was cited to support arguments on retrospective legislation and the rule of law; the Tribunal held it was of tangential relevance at best.
- Misrepresented: Case Law | Bhatt Murphy was cited on legitimate expectation to support the appeal; the Tribunal held it was not relevant and, in any event, outside its jurisdiction.
- Misrepresented: Case Law | National & Provincial Building Society v UK was cited to argue retrospective tax legislation was unlawful; the Tribunal noted the case actually found such legislation lawful.
- Misrepresented: Case Law | Garnmoss was relied upon to suggest HMRC had a general duty to notify HICBC liabilities; the Tribunal held it addressed VAT surcharge notification and did not establish such a duty.
- Misrepresented: Case Law | Hok was cited to support a general HMRC duty to notify HICBC liabilities; the Tribunal held it concerned notification of default and did not create a general duty.
- Misrepresented: Legal Norm | Appellant asserted that his 11 June 2021 phone calls amounted to an appeal notice for s97 FA 2022 purposes; the Tribunal held an appeal must be in writing (s31A TMA) and the calls pre-dated any assessment.
Show 3 additional discrepancies
- Fabricated: Case Law | Verify the existence of the case or cite correctly if it exists.
- Misrepresented: Case Law | James Robertson v HMRC was cited in support of general unfairness arguments; the Tribunal found it not relevant to the issues.
- Misrepresented: Legal Norm | Appellant asserted a general legal duty on HMRC to inform taxpayers of HICBC liability; the Tribunal found no authority and stated no such duty exists under the self-assessment regime.
Questions this record answers
- What happened in Zzaman v. HMRC?
- The Tribunal dismissed the appellant's tax appeal, finding his arguments lacked legal merit. It explicitly addressed the appellant's use of AI, noting that while the tool did not generate fictitious cases in this instance, it provided irrelevant or misapplied authorities that failed to support the appellant's claims, leading to a warning regarding the necessity of human verification for AI-generated legal research.
- Why does Zzaman v. HMRC matter for legal AI risk?
- Even accurate case names can be misapplied by AI—verify that cited authority actually supports your proposition.
- What does the public record establish about Zzaman v. HMRC?
- The record summarizes the outcome described in the linked public source. The recorded document is hosted in the upstream publisher archive. This page is not a substitute for the complete docket, subsequent history, or jurisdiction-specific advice.
- Which source supports this Zzaman v. HMRC summary?
- The recorded source is Damien Charlotin case archive. It is classified as publisher document archive; review the linked material and subsequent docket history before relying on this summary.
Related matters
Related by court, jurisdiction, tool, or classified failure pattern. Similarity does not imply the same facts or outcome.