Taxpayer died on March 13, 2026 prior to E-Filing her return. What do I do?

Enter the date of death in the software - it's in the federal information worksheet.  Then file like you would any other return.

Sounds like the daughter is in charge.  I know my clients and am comfortable when one of the kids steps up to take charge of things.  I would have the daughter sign if I was comfortable that there weren't other siblings that were potentially going to cause a stink.  If you aren't comfortable with the daughter signing, extend and wait until she is officially the executor.

I just completed a return yesterday with the exact same issue. Client passed in January. I spoke to the attorney that's helping the family settle the estate. He said the taxpayer's daughter can sign the return and accept the refund, even if not appointed by the court. I entered the date of death so it would show up at the top of all forms, entered the daughter's info in the In Care Of section of the Client info page, and selected 'Other' on the 1310 along with checking the box for 'Will distribute according to state law' then added her info again in the person claiming the refund section. My state doesn't accept e-file for deceased persons so my client is filing all by mail.