If you received Notice CP-14 from the IRS indicating that you have unpaid taxes for the 2021 tax year, they may have sent the notice in error. The IRS is still backlogged, and as a result, they may not have "registered" your payment in their system.
At this time, don't panic if you received a notice. We hope this issue will resolve itself, and the IRS will issue letters notifying taxpayers of the error. We will continue to monitor the issue and keep you informed of any changes.