Actually Bob I do not know exactly what facility they go to, but I do know that it's the IRS responsibility. I always assumed that the IRS was getting the estimates and the 941 returns, but you may be correct and it may be outsourced. But it doesn't matter as they are responsible. The 941 returns that were screwed up with my clients did NOT have checks attached , they were returns that had refunds that were supposed to be APPLIED to the next quarter . Instead of the IRS applying the refunds, they sent check refunds, but they did not do it until MONTHS after the 941 return was filed, and the subsequent 941 return for the next quarter was given credit by us for the overpayment applied to it. We returned the checks to the IRS along with a letter . They did not process the letters in a timely fashion because of the covid backup. Therefore the subsequent 941 returns were screwed up in their eyes as client was not given credit for the overpayment applied even though the check was returned, And incorrect irs notices followed. This NEVER happened before covid-19 . How hard is it to read a box that is checked APPLY. Therefore it is obvious to me that something happened since the onset of Coronavirus , since this never happened to me even once prior to covid, and I would not be surprised if scanners were being used to read 941 return.  As far as why he used the certified Bank check, I also thought the same thing that you did, and found it to be a little odd. But he has a French first name, even though he is Italian, so that tells me what I need to know.😉🤔