@PATAX  Yes, there is an ES credit on the 2023 account, from a credit-elect on the 2022 return.  This was sent to an elderly couple; one spouse died in early January, so I suspect someone at IRS must have hit the wrong key and meant to send out some sort of condolence letter (although I have never seen one of those from IRS).  It starts out, "we also have no record. . ."  Why the "also"?  No other notice has been received.  

@dkh I haven't responded yet. This was just brought to me yesterday.  I'm waiting to see if they sent the same nonsense to 50,000 other taxpayers, and will issue a Fuggedaboudit notice.