HMRC’s self-assessment registration deadline is fast approaching – who needs to file?

If you work for yourself and earned more than £1,000 in the last tax year (6 April-5 April) or are a partner in a business partnership, you’ll need to complete a self-assessment tax return. This lets HMRC know how much income tax and National Insurance you need to pay for the previous tax year.

It might not be the most exciting thing you’ll do this year, but if you miss the deadlines to register or pay your bill, you could be fined – so it’s important you know what to do and by when.

To help you get to grips with how to do a tax return, this article explains how to register for self-assessment, and the important tax deadlines for your diary between now and January 2022.

This isn’t personal advice though. Tax is a complex subject. If you’re not sure what to do, you should seek professional advice from a tax specialist.

Check if I need to send a self-assessment tax return

How to register for 2020/21 self-assessment tax return

If you’re newly self-employed, or a director of a limited company and you haven’t submitted a tax return before, you’ll need to register for self-assessment first. The deadline for this is 5 October, after the end of tax year which you need to file a tax return for. For example, you must register by the 5 October 2021 if you need to file a tax return for the last 2020/21 tax year (6 April 2020-5April 2021).

The quickest way to register is online. You’ll need to confirm your employment status and have your business’s tax account details to hand. You’ll also need a Government Gateway user ID and password to sign in. If you don’t have a user ID for a business tax account, you’ll be able to create one. Alternatively, you can call HMRC to register.

What happens once I’ve registered?

You’ll be sent a Unique Taxpayer Registration (UTR) number. Make sure you keep this number safe because you’ll need it to complete your tax return and create your self-assessment account. Then HMRC will contact you with an activation code for your account. Once you’ve activated your account, you can file your tax return any time before 31 January 2022.

Check if I need to send a self-assessment tax return

Tax deadlines for your diary

31 October 2021

This is the deadline for most paper tax returns. Even if you’re planning to complete your tax return online, it’s a good date to start getting your ducks in a row. Giving yourself more time to find or re-order any lost paperwork and claim for everything you’re entitled to can make things less stressful. You’ll also have three months to put extra cash aside to cover any shortfall.

30 December 2021

If you’re submitting an online tax return and want HMRC to collect the tax you owe from your wages or pension, you’ll need to submit your return by 30 December 2021. Your bill will need to be less than £3,000 and you’ll need to already pay tax via PAYE to be eligible.

31 January 2022

This is the deadline for completing your online tax returns and for paying the tax you owe. But, if you can help it, don’t leave it to the last minute.

If something goes wrong, it’s unlikely you’ll have time to put things right. For instance, you might not be able to log into the Government Gateway to complete your return and payment, or you could realise you’ve misplaced paperwork and need to order replacements.

There’s usually a second payment deadline of 31 July if you make advance payments towards your bill (known as ‘payments on account’). But if you’re not on this scheme, you’ll usually pay a penalty if you’re late.

Check if I need to send a self-assessment tax return