HMRC v. Gunnarson
Decided 2025-07-23 · Outcome: Warning · AI tool: Unidentified.
AI Hallucination Sanctions — Upper Tribunal (Tax and Chancery Chamber)
1 sanctioned case on record in Upper Tribunal (Tax and Chancery Chamber) where an attorney filed briefs, motions, or other pleadings containing AI-fabricated citations. Every entry below traces to a real, publicly reported court ruling. Data pulled daily from the underlying dockets and reporter databases — last update within 24 hours.
At a glance — Upper Tribunal (Tax and Chancery Chamber)
- Total cases
- 1
- Date range
- all on 2025-07-23
- With monetary penalty
- 0 of 1
- Distinct outcomes
- 1
Outcome breakdown
How courts in Upper Tribunal (Tax and Chancery Chamber) have responded when a filing contained fabricated citations.
- Warning1
AI tool implicated
Filings in this jurisdiction most often cite the tool as “Implied” (the ruling describes an AI-generated brief but does not name a product).
- Unidentified1
What this means if you practice in Upper Tribunal (Tax and Chancery Chamber)
The single documented sanction on record in Upper Tribunal (Tax and Chancery Chamber) concluded with a Warning tied to Unidentified as the implicated tool. One case is not a trend, but it establishes that this court has already surfaced the fabricated-citation issue on the docket — every subsequent filing in Upper Tribunal (Tax and Chancery Chamber) is on notice.
The rulings in this jurisdiction are consistent with the pattern Citation Safe tracks nationally: when a court identifies a fabricated citation, the sanction almost always follows within days, not weeks. The attorney of record — not the AI — is on the hook. Rule 11 (federal), state analogs, and inherent authority all support monetary sanctions, disgorgement, adverse-costs orders, and bar referrals independent of the tool that produced the citation.
Practical implication: any brief that reaches a docket in Upper Tribunal (Tax and Chancery Chamber) needs a citation-existence check before filing. Existence is Layer 1 — the case has to be real. Layer 2 is quote accuracy (any quoted language must actually appear in the opinion). Layer 3 is propositional support (the opinion must actually stand for what you cite it for). Every documented sanction below failed at Layer 1 or Layer 2 — the kind of failure that is trivially catchable before filing and catastrophically visible after.
All documented sanctions in Upper Tribunal (Tax and Chancery Chamber)
Comparable jurisdictions
Other courts on the Citation Safe sanctions database with a similar volume of AI-hallucination rulings on record.
Weeks with a Upper Tribunal (Tax and Chancery Chamber) ruling
Frequently asked questions
- How many attorneys have been sanctioned in Upper Tribunal (Tax and Chancery Chamber) for AI-fabricated citations?
- 1 on record as of the latest daily update. The number is a floor, not a ceiling — only rulings where the court explicitly identified the fabricated citations on the docket are counted. Private reprimands, off-record admonishments, and pre-filing catches do not appear.
- What is the most common outcome in Upper Tribunal (Tax and Chancery Chamber)?
- Warning is the most common recorded outcome (1 of 1 rulings with a coded outcome). Courts vary widely in how they label the same underlying disposition — a “warning” in one docket may functionally equal an “admonishment” or “order to show cause” in another.
- Which AI tools appear most often in Upper Tribunal (Tax and Chancery Chamber) sanctions?
- Unidentified appears most often (1 rulings). Named tools are the exception rather than the rule — most sanctioned briefs are simply described as “AI-generated” in the ruling text.
- Where does this data come from?
- Citation Safe ingests published sanctions rulings from public court dockets and reporter databases (federal PACER, state court publishers, appellate reporters). Rulings are extracted, coded for outcome and tool attribution, and republished with attribution to the source court. See /methodology for the full ingest pipeline.
- How do I make sure I never appear on this list?
- Run every brief through a Layer 1 + Layer 2 citation check before filing. Layer 1 confirms the case exists in a primary source; Layer 2 confirms any quoted language actually appears in the opinion. Both are deterministic checks — not AI second-opinions. Citation Safe offers a free 3-check trial or the Opposition Check $49 flat rate for one-off audits of the other side’s brief.
Verify your own brief before Upper Tribunal (Tax and Chancery Chamber) makes it 2 on this list.
3 free checks. No signup. Every citation checked against the primary source — not another AI. $19 unlocks the full annotated report.
Informational only. Not legal advice. Data derived from public court records; corrections at /contact.