Memory fades, but I’m sure this was clarified sometime in the 90’s, not long after self-assessment guidelines seemed to indicate that it would be reasonable to claim certain costs, including haircuts. An unofficial ‘mates’ memo did the rounds so I suspect there were enough claims being submitted to trigger the Taxman into action. If I recall there was MOD vs Treasury clarification issued, effectively telling us to stop taking the piss.
I remember claiming a monthly haircut and also dining-in nights which were promulgated as parades. It seemed fair enough the way the guidance notes were written and I was not the only one who claimed the tax relief.
My thought process was that if the Taxman insisted on sending a form to complete then why not claim iaw the guidance notes.
It worked the first year. By coincidence (maybe) I then had a very ‘aggressive’ random audit/investigation into my very modest income from rental property, including 100% check of receipts for all claimed expenses. Thankfully I had kept everything but they sure looked hard. Without doubt, if I had falsely declared anything they would have had me. It was rather an unpleasant process, the tone being an assumption of guilt unless you could provide all the original receipts.
I took the hint.