How can I undo / unfile tax returns for previous periods, say 2020 and 2021?

Thank you for vising the QuickBooks Community, Kelvin.

Undoing or unfiling your tax returns in previous years is not available in QuickBooks Online Payroll. If there was a mistake, I recommend asking for advice from your accountant, especially when you need to submit amended forms. You can also refer to your payroll reports if you need some details.

You can always comment below if you have other concerns. We'll always be here to help.