Don't know for sure, with a deceased person. It's my understanding that no matter what, if a refund is due to the deceased person, then the living person that will receive the refund has to mail the signed form 1310 to the IRS with their original signature on it. I've never dealt with that myself, so I don't know if that's an absolute fact or not.
Now while there is an option to indicate no ID is available for the tax filer, I do know that tends to delay the refund. But you're dealing with a deceased tax payer. So it's going to be delayed anyway.
