How early can I submit my 2020-21 tax return?

A Self Assessment return for a particular year can be submitted from the day after it ends.

• The end of the 2020-21 tax year is 5th April 2021.
• A tax return for the 2020-21 tax year can be submitted from 6th April 2021 onwards – the start of the new tax year.

If I submit my Self Assessment, do I have to pay straight away?

The date you submit your Self Assessment doesn’t affect the payment deadline, so filing your tax return earlier in the year doesn’t mean you need to pay your bill earlier, too. Filing earlier simply gives you more time to budget for your tax bill. Which is definitely less hassle than being fined by HMRC for late payment.