HMRC self-assessment process requires you to report your total taxable income and capital gains for the tax year after fulfilling the self-assessment criteria. Thereafter, HMRC calculates the amount of your Income Tax, NICs, and any other payments owed based on the information you submit. Notably, if you are required to submit a self-assessment tax return each year, you must remain heedful of the most crucial self-assessment tax return deadline and the other dates during the tax year to ensure you do not miss them and your self-assessment return is correct and on time.
Important HMRC Self-Assessment Tax Return Deadlines
The following are the essential HMRC self-assessment tax return deadlines you should know to ensure you stay on track for timely and accurate filings:
5 October – Deadline For Self-Assessment Registration
Consider you are a self-employed individual and receive income over the trading allowance of £1,000. Your income will not be taxed at source since the PAYE system does not apply to self-employed income. In this scenario, you will need to register for self-assessment with HMRC. Notably, the deadline for self-assessment registration is 5 October, after the end of the tax year in which you became self-employed. For instance, if you became self-employed on June 1, 2024, you will have until October 5, 2025, to register.
31 October – Deadline To Submit A Paper Tax Return
If you opt to submit your tax return for the previous tax year on paper rather than online, you have until midnight on 31 October of the following year to send it. Hence, HMRC needs to have received your return by 11:59 pm on 31 October, as this is your last day to file your taxes. For instance, if you’re filing for the tax year 2024/25, which ended on 5 April 2025, you need to submit the paper filing by 11:59 pm on 31 October 2025. You should have adequate time to print out the forms, complete them, and send them to HMRC by post.
In order to submit a paper tax return, it is vital to know which HMRC form or supplementary page you need to attach to your main SA100:
30 December – Deadline For Paye Tax Collection
If your income tax bill from self-employment is less than £3,000 and you are also employed somewhere or receiving a company pension, you can ask HMRC to collect tax through your PAYE. Accordingly, HMRC will adjust your tax code automatically to collect tax through PAYE by deducting your salary or pension payments. Now, in order to do that, you have to complete your Self Assessment by 30 December of the year.
31 January – The Most Important Deadline (Filing Online Return And Paying Tax Bill)
31 January is the primary tax return deadline because you must submit your due tax amount for the previous tax year by this date. To clarify, if you want to submit your self-assessment tax return online for the 2024/25 tax year, the final deadline to file it is by midnight on 31 January 2026. In addition to filing you will also pay your tax bill before the self-assessment return deadline.
Did you know that submitting your tax return sooner than the due tax return deadline not only saves you from triggering HMRC penalties, but it can also benefit you in several ways?Â
31 January – Deadline To Make First Payment On Account
It is essential to note that when learning key self-assessment tax return deadlines, the 31 January deadline can be confusing for individuals submitting their returns for the first time. Upon filing the online tax return and settling the tax liability by this tax return deadline in the initial year, the individual is also required to make an advance payment of income tax towards the subsequent year’s self-assessment.
Each payment on account is half of your previous tax bill. For instance, if your self-assessment tax bill was £3,000 for the last tax year (if the tax year is 2024/25), you must pay this amount by midnight on 31 January 2026. Additionally, you will pay £1,500 for the next tax year as a first payment on the account.
31 July – Second Payment On Account
In addition to the first payment on the account, you are also required to make a second payment upfront by 31 July. The second payment on account is also equal to 50% of your previous tax bill. If your income remains the same as last year, then you will have paid your tax in full. If the two payments on accounts exceed the amount you owe in tax, you will be entitled to a tax rebate, and if you still owe some amount after the two payments on accounts, you will have to submit the amount on 31 January of the following year.
Quick Tips for Last-Minute Tax Return Filing
When the tax return deadline is upon you, you can follow a few practical tips in order to ensure your last-minute scramble for submitting your self-assessment is not in vain:
- If your income is over £60,000 and you or your partner has received the child benefit, you must complete the higher income child benefit charge section on your tax return or notify your accountant.
- If your income from property or trading is below £1,000 per tax year, ask your accountant if you are eligible for the new trading and property allowance.
- If the new trading and property allowance applies to you, there is no need for you to complete the property and/or self-employment pages of the tax return as appropriate.
- For the tax year 2025/26, the gains on residential property are taxed at 18%-22%, a much higher rate of Capital Gains Tax.
- You cannot claim a lifetime allowance, as it was abolished as of April 6, 2024.
- Understand the payment on account and the key HMRC payment deadlines.
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Final Word
Filing your taxes on time and not missing key self-assessment tax return deadlines is essential to avoid HMRC penalties. Also, staying aware of the significant HMRC tax return deadlines can help you gain a wider perspective on your tax liabilities and maximise eligible reliefs. However, consistently tracking crucial deadlines can be challenging given your business’s growth demands. A proficient personal tax accountant can free you from the hassles of self-assessment. Your dedicated, accredited accountant will offer you error-free online self-assessment services to ensure your tax return deadline is always met.
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FAQs
What is the deadline for paying the self-assessment tax bill?
There are several important tax return deadlines involved in the self-assessment process, from registering to paying the tax you owe. However, the main deadline for paying your self-assessment tax bill is midnight on January 31st following the end of the relevant tax year. For instance, to submit your tax bill for the most recently completed tax year (April 6th 2024, to April 5th 2025), the tax payment deadline is January 31st, 2026.
What is the last day to submit your paper tax return?
If you choose to submit your tax return via post rather than online, the last day to file your taxes on paper is midnight on 31 October. Hence, HMRC must receive your tax return by 11:59 pm on 31 October.
What is the deadline to make the first payment on account for the self-assessment tax return?
After you have filed the online tax return and settled the tax liability by the 31 January tax return deadline, you are also required to make an advance payment of income tax towards the next year’s self-assessment. It is called the first payment on account. Each payment on your account is half the amount of your previous tax bill.
