At the start of January 2024, 5.7 million people were yet to file their return for the previous year, with nearly 50,000 people choosing New Year's Eve or New Year's Day to tick it off their list.

HMRC is encouraging people to not wait around, and instead submit their 2023-24 tax return early and allow themselves more time to plan and budget for payments ahead of the deadline.

When is the Self Assessment tax return deadline?

This depends on how you submit your return:

• For online tax returns, the deadline is January 31st 2025.​​​​​​
• For paper tax returns, the deadline was October 31st 2024.

Important: January 31st 2025 is also the deadline for paying any tax owed. There’s usually a second payment deadline of July 31st if you make advance payments towards your bill (known as ‘payments on account’).

Penalties for late filing and paying tax owed

Penalties for late filing start with a fixed £100 penalty, with greater financial penalties coming after 3, 6 and 12 months, depending on how late the return is filed. There are also penalties for paying any tax owed late, with interest also charged on any tax paid late.

Check if you need to send a Self Assessment tax return

If you're not sure if you are still required to complete a Self Assessment return, you can check via this online tool and learn more details here.

How to submit your tax return

People can submit their tax returns and pay any tax owed by logging into their Government Gateway account on GOV.UK. You'll also need your Unique Taxpayer Reference number.

For details on how to log in, or how to set up a Government Gateway account if you have yet to do so, visit the 'File your Self Assessment tax return online' page on GOV.UK.

Are you completing a tax return for the first time?

You must tell HMRC if you need to complete a tax return and have not sent one before. You can do this by registering for Self Assessment here.

If you didn't send a tax return last year

If you’ve registered for Self Assessment before but did not send a tax return last year, you must register again to reactivate your account.

If you want the tax you owe to be collected from your wages or pension

Submit your online return by December 30th if you want HMRC to automatically collect tax you owe from your wages and pension. Find out if you are eligible to pay this way.

Need help with your tax return?

There are lots of tools and resources available to help, including: 

• HMRC's digital assistant  - the assistant will help you find information, and if you can’t find what you’re looking for you can ask to speak to an adviser
• Guidance notes and help sheets with a wealth of information
• A series of video tutorials
• Live and recorded webinars
  • Starting your online tax return
  • Filling out the self-employment section of your tax return
  • Filling out the employment section of your tax return
• Download the HMRC app
• Subscribe to HMRC email updates for the latest information on Self Assessment

Do you need technical support?

Find technical support for help signing into HMRC online services.

Do you need extra or specialist support?

You can get extra support if your personal circumstances make dealing with taxes and tax returns difficult. For example, if:

• you have dyslexia, autism or cognitive difficulties
• you have reduced mobility or physical disabilities
• you have sensory disabilities, like a visual, hearing or speech impairment
• you have mental health conditions, like depression, stress or anxiety
• you’re experiencing financial hardship - for example you cannot afford essentials like food, bills or rent (you may be able to pay in instalments)
• you’re a victim of domestic abuse, including economic abuse
• you're a refugee or migrant
• English is not your first language and you require an interpreter
• you’re receiving treatment in hospital

For support on the above, you can contact a voluntary or community sector organisation who can provide you with help and advice, or contact HMRC via the links here.

Beware of scams

Be aware of the risk of falling victim to scams that mention HMRC and tax returns. Never share your HMRC login details with anyone. HMRC provides advice on how to deal with scams.