Incident Tracker

HMRC v Gunnarsson, [2025] UKUT 247 (TCC)

dismissal

Before the Upper Tribunal (Tax and Chancery Chamber), unrepresented respondent Marc Gunnarsson cited three non-existent First-tier Tribunal decisions produced by online AI software. The Upper Tribunal set aside the FTT decision, dismissed his appeal and confirmed recovery of £12,918 in wrongly claimed grants, warning that AI chatbots frequently mislead litigants in person.

Date of decision/order

2025-07-23

Court

Upper Tribunal (Tax and Chancery Chamber)

Jurisdiction

UK

AI tool

Not identified in the record

Conduct

An unrepresented respondent cited three non-existent First-tier Tribunal decisions (Patel, Ali and Kamran v HMRC) in his skeleton argument. He acknowledged using online AI software to prepare his submissions; the fabricated authorities were removed in an amended skeleton the same day.

Consequence

See outcome