Tailor your return 29 - If you are acting on behalf of someone else?

These will be exceptional circumstances.

The following people are authorised to complete a return on behalf of someone who is not mentally capable of understanding it:

• a Receiver appointed by the Court of Protection in England and Wales
• a Curator Bonis appointed by the Office of the Accountant of Court in Scotland
• a Controller appointed by the Office of Care and Protection in Northern Ireland
• an Attorney appointed under an Enduring Power, registered in the appropriate court
• any person so authorised by any of the above courts

If you are an executor acting on behalf of someone who has died you cannot file a return online. Find out more information about Self Assessment tax returns: Returns for someone who has died.

If you have not previously supplied evidence of your appointment you should send the original document or a certified copy to HMRC by post do not send as an attachment to an online return.