Self Assessment Tax Return Deadlines 2024/25

Missing the Self Assessment deadline can result in hefty penalties from HMRC. This comprehensive guide covers everything you need to know about self assessment tax return deadlines for the 2024/25 tax year.

Key Deadlines for 2024/25

5 October 2025

Registration Deadline: If you need to complete a tax return for the 2024/25 tax year and have not sent one before, you must register by this date. This applies to new self-employed individuals, landlords, or anyone with untaxed income.

31 October 2025

Paper Tax Return Deadline: If you are filing a paper tax return, it must be submitted by this date. HMRC will then calculate the tax you owe and notify you. We strongly recommend filing online for a later deadline.

31 January 2026

Online Tax Return & Payment Deadline: This is the most important deadline. Your online tax return must be filed and any tax owed must be paid by midnight on 31 January 2026. Late submissions incur automatic penalties.

31 July 2026

Second Payment on Account: If you made payments on account, the second payment is due by this date. This is 50% of your previous year's tax bill (unless you reduce it or opt out).

Late Filing Penalties

Penalties for Missing the Deadline

HMRC penalties increase the longer you delay filing your return:

1 day late: £100 fixed penalty (even if no tax is owed)

3 months late: Additional £10 per day (up to £900) for a maximum of 90 days

6 months late: Additional £300 or 5% of the tax due (whichever is greater)

12 months late: Additional £300 or 5% of the tax due (whichever is greater), plus potential investigation by HMRC

What You Need to Prepare

To complete your Self Assessment, gather the following documents and information:

Income Documents

P60 from employer
P11D for benefits
Self-employment income records
Rental income statements
Investment income certificates

Expense Records

Business expenses receipts
Mileage logs
Bank statements
Pension contributions
Charitable donations

Pro Tips for Meeting the Deadline

Start Early

Don't wait until the last minute. Start gathering your documents in December to give yourself plenty of time to complete and review your return.

Keep Records Throughout the Year

Maintain organised records of income and expenses throughout the year. This makes the process much smoother when it's time to file.

Use Accounting Software

Cloud-based accounting software like Xero or QuickBooks can automatically categorize transactions and make it easier to generate reports for your tax return.

Consider Professional Help

An accountant can ensure your return is accurate, maximise your allowable deductions, and save you time and stress. The cost is often outweighed by the tax savings and peace of mind.

Need Help with Your Self Assessment?

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