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. Self-employed income is generally not taxed through PAYE, although deductions at source can apply under schemes such as the Construction Industry Scheme (CIS). 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 it from your salary or pension payments. To qualify, submit your online return by 30 December following the tax year, or your paper return by 31 October. HMRC must also be able to collect the bill within its PAYE deduction limits.
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?
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 may also need to make an advance payment of income tax towards the subsequent year’s self-assessment.
Payments on account are normally required unless the previous year’s relevant tax bill was under £1,000 or more than 80% of the tax was collected outside Self Assessment.
Each payment on account is normally half of the previous year’s relevant Income Tax and Class 4 NIC liability, excluding Capital Gains Tax and student loan repayments. This example assumes payments on account apply, the £3,000 consists entirely of relevant Income Tax and Class 4 NICs, and no payments on account have already been made towards that 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 account.
31 July – Second Payment On Account
If payments on account apply to you, the second payment is due on 31 July. The second payment on account is normally calculated on the same basis as the first, using the previous year’s relevant Income Tax and Class 4 NIC liability. A balancing payment may still be due if your final liability exceeds your payments on account, including for Capital Gains Tax or student loan repayments. If the two payments on account 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 account, 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 you are liable for the High Income Child Benefit Charge, include it on your tax return or notify your accountant. The charge applies where adjusted net income exceeds £60,000; if both partners exceed this threshold, the higher-income partner pays it.
- If your gross property income or gross trading income is £1,000 or less per tax year, ask your accountant if you are eligible for the new trading and property allowance.
- If your income qualifies for full relief under the relevant allowance, you generally do not need to report it, subject to HMRC’s exceptions.
- For the tax year 2025/26, individuals’ taxable gains on residential property are taxed at 18% or 24%, depending on their taxable income and the size of the gain.
- 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 the most recently completed tax year, 6 April 2025 to 5 April 2026, the standard deadline for filing your online Self Assessment return and paying any balancing tax due is 31 January 2027.
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 may also need 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 account is half the amount of your previous tax bill. Payments on account are normally required unless the previous year’s relevant tax bill was under £1,000 or more than 80% of the tax was collected outside Self Assessment.
