I'm sorry for your loss.
Print out the return and sign your own name. Write "Personal
Representative" next to your signature.
When filing a return on behalf of a deceased person, unless you are the
spouse, you must file additional documents:
- If you’re
the court-appointed executor, attach a copy of the court document that
authorizes you to act. This may be called your “Letters Testamentary,” or
something similar, depending on the state.
- If a court
hasn’t appointed you to represent the estate, file IRS Form 1310,
Statement of Person Claiming Refund Due a Deceased Taxpayer, with the
return.
For additional information, please see IRS Pub. 559 - Survivors, Executors,
and Administrators