The deadline to file UK 2021 tax return and pay any tax due remains 31 January 2022. The penalty waivers will mean that:

1. anyone who cannot file their return by the 31 January deadline will not receive a late filing penalty if they file online by 28 February

2. anyone who cannot pay their Self Assessment tax by the 31 January deadline will not receive a late payment penalty if they pay their tax in full, or set up a Time to Pay arrangement, by 1 April

However - Interest will be payable from 1 February, as usual on any unpaid tax, so it is still better to pay on time if possible.