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When is the tax return deadline?

  • 3 min read
  • Last updated 17 Apr 2024

If you don’t know the tax return deadline, you must be new to the world of Self Assessment. If you’re not, then we assume you’re a natural risk-taker, playing with financial well-being fire!

I’m a first-timer

Filing and paying your first tax return can feel very scary – especially if you’re worried about making mistakes, or making sure you pay the money you owe on time.

But don’t worry! As long as you prepare ahead of time and complete the tax return before the deadline, you have nothing to worry about. 

Read on to find out everything you need to know about the tax return deadline.

Self-assessment tax return explained

Self Assessment is basically the way that you declare and pay your taxes to HMRC. 

You’re taxed on income that you earn each tax year. This runs from 6th April – 5th April every year. You must tell HMRC about your untaxed income through a tax return, where you detail all your income and business spending. 

They will then calculate any tax you owe based on your profits.

If you don’t file your tax return or pay what you owe before the deadline, you could land in a lot of trouble with HMRC. Eek! Here’s everything you need to know. 

Who has to file a tax return before the deadline?

A Self Assessment tax return is the way that many self-employed workers declare and pay tax, but there are many other reasons why you might earn untaxed income, such as:

  • You have another source of income alongside your full-time job (a side gig)
  • You’re a landlord 
  • You have capital gains from investments
  • You make a profit from selling assets (e.g. a house)
  • You’re claiming pension tax relief

If any of the above apply to you, you have to register for Self Assessment and file a tax return with HMRC before the deadline. 

When is the tax return deadline?

There are two key deadlines that you need to know about for Self Assessment:

  1. The deadline to register for Self Assessment, which is the 5th of October in any given year. You have to do this if you’ve never done a tax return before.
  1. The Self Assessment deadline for online returns – which is the 31st of January the year after the tax year you’re paying for. So, if you are paying tax for your 2023/2025 tax return, this should be done before the 31st of January 2026.

Test your knowledge📚

Take our deadlines and penalties quiz to see if you’ve got all the information down 💪 (or if you need a little more work – either is fine 😅)

I want to file a paper tax return – is the deadline different?


Although most tax returns tend to be filed and paid through HMRC’s online service, it’s still possible to file your tax the old-fashioned way. However, if you choose to file a paper return instead of completing it online, the deadline is different.

The deadline to file a paper return is 31st October. This is a lot earlier than the deadline for an online return, so you’ll need to make sure you’ve filled out all your forms and have posted them to HMRC (make sure you account for postage time!).

The main Self Assessment tax return form you’ll need to send is SA100, but there are other supplementary forms that you would need to fill out based on your situation. We’ve listed these forms for you here:


Hassle-free tax returns with TaxScouts

Need help sorting your tax return? At Taxscouts, we offer hassle-free tax returns! Get in touch to see how we can help you.

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