I prepared 2021 through 2024 returns for a nonfiler taxpayer who died in 2024.  Refunds of about $2,000 for each year. Too much federal tax withheld on state pension, no tax withheld for state.  Owed about $1,000 each year to the state, where the Revenue Department doesn't do a match to check if its own pension recipients are filing.  Anyway, we filed 2021 in mid-March, waited a couple weeks to file 2022 and 2023, then waited another two weeks to file 2024.  Sometimes, IRS will freeze an account if prior years haven't been filed and processed.  Attached Form 1310 and Letters of Personal Representative to all returns. 

The 2022 and 2023 refunds have already been received.  2024 is still being processed.  For 2021, we received one of those "identity theft" letters asking the decedent to give IRS a phone call with the return in front of him.  When calling IRS, you listen to a couple minutes of irrelevant blather, then press 3 to be transferred to the right section.  Where, the recording tells you they have too many phone calls, please call back later, and hangs up.  

I bill for wasted time, and my client the PR lives 200 miles away and can't be by my side to help with phone calls.  We sent a Form 911 to the Service Center TAS.  Figure it will take a couple months for someone to sort it out, but that means they have to pay interest.  The 2022 and 2023 refunds came within 45 days, so no interest was required.