While as a general principle, Income Tax Self Assessment returns which are filed on paper after 31 October can attract a penalty, HMRC recognise that situations can arise where the application of a penalty is inappropriate, but a claim must be made for this treatment.

Going forward, a reasonable excuse claim must be made in writing in a letter attached to the paper tax return, or on a special claim form. It must include the following information:

• Either the error message or details of the error message which appeared where the attempt to file electronically failed.
• The UTR (Unique Taxpayer Reference).
• The authorised agent name, address and contact details (if appropriate).
• The reason for claiming reasonable excuse.
• The date you tried to file a particular return online or realised that it could not be filed online.
• The date of claim.

According to the HMRC statement “HMRC does not want to penalise customers who have made a genuine attempt to file online and therefore a reasonable excuse claim received without details of the appropriate error message will be considered sympathetically on its merits.”