Not sure I understand....the 2021 program and it will only generate a 2022 estimated payment voucher.

You cant accidently print out a 2021 estimated voucher using the 2021 program.

Ohh, but there were some issues at one point that were printing the wrong year on some forms, but that was fixed in an update months ago...you may want to update your program.

But the client already sent it to the IRS

Have the client create an IRS Online account so they can see where that payment was credited....if they did credit it to the wrong year, it should be refunded (assuming the client doesnt owe anymore money for that wrong year).

I'd agree w/ Lisa.  If the money is in the wrong tax year you might file an amended return including the estimated payment and requesting refund that way