its possible if taxpayer underpaid or missed an estimated tax payment.

"Showing estimated tax penalty in error"

Are you really sure?  Providing some numbers might help.

Just be aware that the form 2210 is not ready for filing (efile or paper) yet, and yes there are computation errors on it. At this point when I open one it says ready 2-17, so we will see. If you look at part III you will see that it still has payment due dates of 2020 rather than 2021.

Probably want to wait a few days and see if it does get updated this week.

There can still be a penalty if you did not pay sufficient estimates in a timely manner...

"if you did not pay sufficient estimates in a timely manner"

Or if enough withholding wasn't paid in.

Iron Man that may be the solution there if the estimate dates aren't fixed , , I.E. we can have the clients increase their withholding, if possible,, instead of giving them estimates...