Deborah Parkinson

Hi My son left the UK April last year, he informed his accountant at the time and was under the impression that as he hadn't traded as self employed since the previous tax year of which he did his self assessment his accountant would tie up any loose ends, now I have received a letter from HMRC addressed to him saying he has been fined for not sending his tax return on time, does anyone know who I would contact to inform about this, he is currently in Indonesia so can't phone himself due to cost and can't email, I did email his accountant but haven't had a reply ( guessing he isn't interested with my son no longer being a client ) even though my son won't be returning to the UK he doesn't want HMRC chasing him when he hasn't been self employed since January 2023 and his business ran at a loss for the year 2022/2023 any help as to which department I need to ring would help tremendously