What Has HMRC Announced?

In guidance published on 8 October 2026, HMRC encouraged Self Assessment customers to begin their tax returns early rather than waiting until the final weeks before the deadline. The announcement comes ahead of World Mental Health Day on 10 October and highlights the stress that financial deadlines can cause.

An HMRC-commissioned survey involving more than 5,200 customers found that over 26% said they experienced anxiety when a tax or financial deadline was approaching. HMRC says completing a return in manageable steps may help people feel more prepared.

Taxpayers can start an online return, save their progress and return to it later to add information or check their answers before submitting it.

Official announcement: HMRC encourages taxpayers to start early.

Important Self Assessment Deadlines for 2026–2027

The return covered by this announcement relates to the 2025–2026 tax year, which ran from 6 April 2025 to 5 April 2026. Taxpayers should check which filing method applies to them and make sure HMRC receives the return by the relevant deadline.

The dates above reflect HMRC guidance. Different arrangements may apply to some customers, so check your personal HMRC account and any letter HMRC has sent you.

Official guidance: Self Assessment tax return deadlines.

Why Should You File Your Tax Return Early?

Submitting a return before the deadline can offer several practical advantages. HMRC identifies the following benefits of early filing:

• Know your tax bill sooner: You can estimate how much money you need to set aside and plan your finances ahead of the payment deadline.
• Potentially receive a refund sooner: If your completed return shows that you have overpaid tax, an early submission may allow your refund to be processed sooner.
• Reduce last-minute pressure: Starting early gives you more time to gather documents and work through the form in stages.
• Check for mistakes: You have more time to review figures, identify missing information and make corrections before submitting the return.
• Obtain proof of income: A processed tax return may help when evidence of income is needed for a mortgage, loan application or benefit claim.

Importantly, submitting a tax return early does not normally mean that the tax payment must also be made early. The standard payment deadline for the 2025–2026 return remains 31 January 2027.

Read HMRC guidance: Benefits of submitting your tax return early.

Who May Need to Complete a Self Assessment Tax Return?

Self Assessment is used to report income and certain tax liabilities that are not fully dealt with through normal PAYE deductions. Depending on their circumstances, people may need to submit a return if they:

• Were self-employed as a sole trader and earned more than £1,000 before allowable expenses and tax reliefs.
• Were a partner in a business partnership.
• Received taxable income from renting out property or land.
• Had taxable savings interest, dividends, foreign income or other income that was not fully taxed at source.
• Need to report Capital Gains Tax or a High Income Child Benefit Charge that is not being paid through PAYE.
• Received a notice from HMRC requiring them to submit a tax return.

These are examples, not a complete list. Whether a return is required depends on the individual circumstances and the rules applying to the relevant tax year.

Official guidance: Who must send a Self Assessment tax return.

What Should You Prepare Before Starting?

Preparing the necessary information before opening the online form can make the process easier. The documents you need will depend on your income sources and personal circumstances.

• Your National Insurance number and Self Assessment login details.
• Your Unique Taxpayer Reference (UTR), if applicable.
• Employment income and tax information, such as a P60 or P45 where relevant.
• Records of self-employment income, allowable business expenses and invoices.
• Property rental income and relevant expense records.
• Bank statements, savings interest, dividend statements and details of other taxable income.
• Records of pension contributions, Gift Aid donations and other relevant reliefs or claims.
• Details of tax already paid or payments on account, where applicable.

Keep records that support the figures you enter. Do not submit estimates as confirmed figures without checking whether they are appropriate under HMRC rules.

How to Start Your Self Assessment Return Online

1. Check whether you need to file: Use the official HMRC checker if you are unsure whether a return is required.
2. Sign in to HMRC: Access your Self Assessment service through GOV.UK.
3. Register if required: If you are filing for the first time, complete the relevant registration process and obtain the required details.
4. Gather your records: Collect income statements, expense records and details of tax already paid.
5. Complete the return: Enter information that applies to your circumstances and check each section carefully.
6. Review and submit: Check the figures, submit the return and save the confirmation for your records.
7. Plan your payment: Check the amount due and arrange payment by the applicable deadline.

What If You Have Not Registered Yet?

People who need to complete a return for the 2025–2026 tax year and are not already registered generally needed to notify HMRC by 5 October 2026 if they had not filed before, or had previously registered but did not need to file for 2024–2025.

That registration date has now passed. If you believe you should have registered but have not done so, check HMRC guidance and take action as soon as possible. HMRC states that people registering after 5 October may receive a different filing deadline, usually three months from the date of the letter or email they receive. The normal deadline to pay tax owed remains 31 January 2027.

If you were registered previously but did not file last year, you may need to reactivate your Self Assessment account. Check your account and follow the official instructions rather than assuming that an old registration is still active.

Official guidance: Registering for Self Assessment.

What Are the Penalties for Filing Late?

Missing a Self Assessment deadline can lead to penalties even when no tax is owed. Under the standard rules, late filing can result in:

• An initial fixed penalty of £100.
• After three months, daily penalties of £10, potentially reaching £900.
• After six months, a further penalty of 5% of the tax due or £300, whichever is greater.
• After twelve months, another penalty of 5% of the tax due or £300, whichever is greater.

Late payment can lead to separate penalties and interest. The exact amount depends on the circumstances and the length of the delay. If you cannot pay your bill in full, contact HMRC or check whether a payment arrangement is available instead of ignoring the bill.

Check current official rules: Self Assessment penalties.

Can You Spread the Cost of Your Tax Bill?

Taxpayers who are concerned about paying a large bill in January should review their options in advance. HMRC provides information about budgeting for Self Assessment and may allow eligible customers to arrange payments towards a future bill.

Payment options and eligibility depend on the customer and their circumstances. Check the official guidance before setting up a plan, and do not assume that a payment arrangement automatically removes the need to file on time.

Official guidance: How to pay your Self Assessment tax bill.

Frequently Asked Questions

Final Summary

HMRC is urging taxpayers to start their 2025–2026 Self Assessment returns early so they have time to organise their records, check their information and plan for any tax due. The key dates are 31 October 2026 for paper returns and 31 January 2027 for online returns and the standard payment deadline.

Taxpayers who are unsure whether they need to file, have missed a registration deadline or cannot pay their bill should consult official HMRC guidance as soon as possible. Starting early can make the process more manageable and help reduce the risk of avoidable errors or penalties.