If you prefer to fill in your tax return on paper, you have until midnight on 31 October 2024 to deliver it to HMRC. If you miss the deadline you’ll be fined £100 with the possibility of additional fines depending on how late your return is. If HMRC’s request that you complete a 2023/24 tax return was dated 1 August 2024 or later, the deadline for submitting the form on paper or online is three months from the date of HMRC’s request.

HMRC doesn’t publicise it, but there are circumstances where it will accept a paper 2023/24 tax return after 31 October, though not later than 31 January 2025 unless the tip above applies, without fining you.

Check HMRC’s list of exceptions where paper tax returns are accepted. Also check the list if you intend to file your tax return online in case your circumstances require you to file on paper.

If you’re going to miss the 31 October deadline, you can still avoid a fine by submitting your return online. If you haven’t already done so, you’ll need to sign up for HMRC online services which gives you the option of completing and submitting your tax returns online. Alternatively, you can buy self-assessment software from as little as £20 which allows you to complete your return on-screen and submit it electronically.

Don’t forget that there’s also a fine for paying your self-assessment tax late. Whether you file your self-assessment return on paper or online, the normal deadline for paying the tax you owe for 2023/24 is 31 January 2025.