Do I Need to File a Self-Assessment Tax Return

Filing a Self-Assessment Tax Return is essential for self-employed individuals and anyone earning income that isn’t taxed at source. By understanding the process, meeting deadlines, and preparing thoroughly, you can avoid penalties and effectively manage your tax responsibilities in the UK.

Stay on top of your UK tax obligations with the Self-Assessment system - use helpful guides to manage deadlines and filing.

Who Needs to File a Self-Assessment Tax Return?

If you're self-employed, you're required to report your income and calculate your own income tax by completing a self-assessment tax return each year. Even if you're employed, you may still need to file if you receive additional income that isn't taxed at source, such as rental, savings, dividends, foreign income, etc. For detailed guidance, visit HMRC's website

Key Dates to Remember

The UK tax year runs from 6 April to 5 April of the following year. Be sure to remember these key deadlines:

Online Submission and Tax Payment: Midnight on 31 January following the end of the tax year.
Paper Submission: 31 October following the end of the tax year (the tax payment deadline
remains 31 January).

Registering for the First Time

If you’re filing for the first time, register for Self-Assessment by 5 October after the end of the tax year you’re reporting for. You can register online, by post or by phone. Upon registration, you’ll receive a Unique Taxpayer Reference (UTR), a 10-digit code necessary for submitting your tax return.

Preparing to File

Before starting your tax return, gather the following information:

Your UTR and National Insurance number.
Details of untaxed income, such as self-employment earnings, property income, interest, dividends, etc.
Relevant forms, such as P60, P45, or P11D, for income taxed at source.
Records of self-employed business expenses.
Information on eligible pension or charitable contributions.

How to File Online

HMRC’s online portal makes the filing process straightforward. Follow these steps:

Log into your personal tax account using your Government Gateway ID.
Complete the Self-Assessment (SA100) form, which covers income and allowances.
Add supplementary pages for additional income types (e.g., rental or foreign income).
Review your entries for accuracy.
Submit your return and save the confirmation for your records.

Tax Payments

Ensure your tax liability is paid by 31 January to avoid late payment interest. You may also need to make Payments on Account, which are advance payments for the next tax year. These are due on 31 January and 31 July, and are typically half of your previous year’s tax bill. For example, if your 2023/24 tax bill is £2,000, you’ll pay £1,000 each in January and July 2025 toward your 2024/25 tax liability.

Making Tax Digital (MTD)

From 6 April 2026, the UK government’s MTD initiative will require individuals with self-employment income, property income, or a combination of both, exceeding £50,000 gross annually to: