Registering for Self Assessment

If you need to file a Self Assessment tax return for 2024/25, you must register by 5 October 2025 to avoid a penalty and ensure you receive your Unique Taxpayer Reference (UTR) in time. You can register yourself or through an agent via Gov.uk. Late registration may result in a failure to notify penalty.

You must register if you had new untaxed income in 2024/25, such as self-employment, a side hustle, or property rental. However, registration isn’t required if your self-employment income is under £1,000, or your rental income is below £1,000 (or under the £7,500 rent-a-room limit, £3,750 each if shared).

It may take up to 21 working days for confirmation after registration.

The filing deadline is 31 January 2026, with a £100 penalty for late submission.
Tax due must also be paid by 31 January 2026, including a payment on account (50%) if your tax bill exceeds £1,000.