After my wife died in 2012 I discovered that due to some kind of clerical error at the IRS I had been marked DECEASED in 2013. I was never notified of this and the only way I found out was when I started making inquiries about my long overdue tax refund. I contacted and worked directly with the Taxpayer Advocate's office. I had filed my taxes (paper forms back then) well before the April 15th deadline for my 2013 taxes in 2014. It was not until February 2015 that I finally received my refund. I don't remember if I got any interest on it then or not. The refund was not that large and the interest would have been minimal I think. I never received any explanation of what happened other than some sort of systems or clerical problem between the IRS and the Social Security Administration. I don't think it was on the SSA side since they kept paying my Social Security Benefits the entire time that the IRS considered me dead.
Fast forward to my 2019. Note that this is EXACTLY 7 years after the first incident described above. This also happens to be the standard IRS records retention period. I was again marked DECEASED and my account locked and frozen by the IRS. This time, however, I was getting a MUCH larger refund due to some extra withholding that I forgot to change. Also 2020 was the year we began COVID-19 problems. Again, I filed in mid March of 2020. I began checking the IRS's "Where's My Refund" web site in April or May, and when it showed no indication that they had even received my return I began trying to contact the IRS again. This time, however, due to COVID-19 there was nobody at the IRS that I could get in touch with at all. Finally, I reached out to my Congressman's office and they took over from me in getting in touch with the IRS Taxpayer's Advocate's Office. This was probably in July of 2020. Over the summer I had to resubmit all of my returns and other documents through my Congressman's office for forwarding to the IRS along with images of documents to prove I was still alive. It was not until June 2021 that I received a notice from my Congressman's office that I was again alive in the IRS view and that my account was unlocked, but still Frozen until an upper level manager could unfreeze it. Eventually on September 10, 2021 I got the notice that my refund check was being issued and I was to receive an extra $62 in interest for the delay. $62 interest on a large refund delayed over 17 months! The IRS was apparently not wanting to pay me interest on the time that their "System" considered me deceased. Using published data from the IRS I was able to calculate that the proper amount of interest for the size and lateness of my refund should have been about $400. I did get the check for the refund and the $62 in interest they calculated on Friday September 24, 2021. I have not yet cashed that check. We are still in discussions on the remaining interest I am owed.
Since the IRS has twice declared me deceased, although I was till paying withholding into my "Closed/Frozen" account, and I was never notified of this declaration, I think that ANY system changes at the IRS should be directed to just FIX THEIR DAMN SYSTEMS FIRST!
I still have no word on the status of my 2020 return filing, which I had to file on paper in March of 2021, since an attempt to file on-line informed me that I was still dead. This time I sent it with tracking and I have documentation that it was delivered.