HMRC reasonable excuse: the Perrin test and what actually counts

The Perrin test

The Upper Tribunal in Perrin v HMRC [2018] UKUT 156 set the structured test HMRC and tribunals apply:

The four questions

• What facts does the taxpayer say give rise to a reasonable excuse?
• Are those facts proven on the balance of probabilities?
• Do they amount to an objectively reasonable excuse for the default?
• Did the taxpayer put things right without unreasonable delay once the excuse ended?

Excuses that typically work

• Serious illness, disability or a mental health crisis, ideally with medical evidence.
• Bereavement of a close family member around the deadline.
• Fire, flood or theft that destroyed your records.
• An unexpected, documented HMRC online-service or software failure.

Excuses HMRC rejects

• 'I found the return too difficult' or 'I did not get a reminder'.
• Relying on someone else (an accountant) unless you took reasonable care.
• Not having the money to pay (though this can support a separate case).
• Pressure of work or being too busy.