You will want to file on behalf of the decedent if he or she had income tax withheld and would be entitled to a refund. Otherwise, to determine if someone must file a tax return for the decedent, you can refer to IRS Publication 17 or answer the questions on this IRS website: http://www.irs.gov/individuals/article/0,,id=96623,00.html.
Note: This guide addresses only a tax return for the income earned while the decedent was alive. Income earned on the decedent's assets after the date of death is reported on a different tax return and is not addressed here.
Determine Who Should File
If the decedent was married, his or her surviving spouse can still file a joint return including the surviving spouse's income for the year and the deceased spouse's income until the date of death.
If a married filing joint return is not appropriate, then the personal representative or executor appointed for the estate should file the return. If no personal representative or executor was appointed, then whomever was handling the deceased person's property must file. If there is no one person handling the deceased person's property, the IRS may determine that the person or persons who received the deceased person's property should file.
Note That the Taxpayer is Deceased
You should enter the Taxpayer's standard name, social security number and address in the place provided at the beginning of the return. If filing jointly you should list both taxpayers.
However, you should also write "Deceased," the deceased taxpayer's name, and the date of death across the white space at the top of the return. If you don't do this, it may create delays or errors in processing the return.
Provide Appropriate Documentation
If you are not the surviving spouse and the deceased was entitled to a refund, you will need to either (a) attach the court documents that appointed you executor or personal representative or (b) if there was no court appointment, complete and attach IRS form 1310 (Statement of Person Claiming Refund Due a Deceased Taxpayer).
Sign the Return
If you are the surviving spouse, you should identify that you are signing the return as Surviving Spouse. If an executor or personal representative was appointed, he or she must sign the return (even if the surviving spouse is also signing the return).
If this is not a joint return, the personal representative or executor should sign the return and identify himself or herself as such. If there was no personal representative or executor appointed, the person who is filing on behalf of the decedent should sign it.