Filing a deceased person's tax return.

Yes you need it. The estate is not the taxpayer and she has no surviving spouse.

This is a final personal tax return for a deceased person, not an estate.  Instructions say "If a taxpayer has a refund amount that is being claimed by an individual other than the surviving spouse or personal representative appointed by the court, which is the case in my client's return, then Form 1310 must be filed.  So, I shouldn't have to attach the Form 1310 and file it manually.  I should be able to electronically file it, not manually, without attaching Form 1310, but the program will not allow me to do that.  That is my frustration.

IRS does not follow their own instructions. They won't process the tax return without a 1310. Then, even though you submit it with the return, they'll send a letter asking for it. It will take at least 6 months, probably more to get the refund.

I've never been able to get a return with a 1310 to efile. Others seem to have a magic touch.

"Others seem to have a magic touch."

It's better to be lucky than good. 😁 

Form 1310 itself says, "Don’t file Form 1310 if you are claiming a refund on behalf of a deceased taxpayer, and: . . .You are a personal representative (defined later) filing, for the decedent, an original Form 1040, 1040-SR, 1040-NR, or 1040-SS that has the court certificate showing your appointment attached."

If you can't do that with e-filing, print out the return and tell the PR to sign it and mail it to IRS.  The next problem you will have is whether they will do a direct deposit to an estate account with an EIN.  

And the IRS will still send a letter asking for a 1310.

past performance is not indicative of future results

Thank you everyone.  It's been an interesting return to file to say the least.  I've already decided to manually have them file the Federal return with Form 1310 and with the "Letter of Appointment" from the State for the executor.

"past performance is not indicative of future results"

True. But it always happens for me. I warn the client it will happen.