When to Register for Self Assessment: Don’t Miss the Deadline

Wojciech

Diploma in Professional Accounting
Diploma for Financial Advisers
HMRC Authorised Tax Agent

Even if your self-employed profits are below the Personal Allowance and you don’t anticipate owing any Income Tax, if your gross self-employment income surpasses the £1,000 Trading Allowance in a tax year, you are legally obligated to register for Self Assessment with HMRC. This is a critical step to ensure you are compliant with tax regulations.

The deadline for registering for Self Assessment is typically 5 October following the end of the tax year in which you started self-employment or your income first exceeded the £1,000 threshold [3]. For example, if you began self-employment and earned more than £1,000 between 6 April 2024 and 5 April 2025 (which is the 2024/2025 tax year), you would need to ensure you are registered by 5 October 2025. Once you successfully register, HMRC will provide you with a Unique Taxpayer Reference (UTR) number. This UTR is essential for filing your annual Self Assessment tax return.

Beyond registration, there are also important deadlines for filing your tax return itself. For online submissions, the deadline is usually 31 January following the end of the tax year. So, for the 2024/2025 tax year, your online Self Assessment tax return would be due by 31 January 2026. Missing these deadlines can result in penalties, so it’s crucial to be aware of them and plan accordingly. Keeping accurate records of your income and expenses throughout the tax year will make the process of completing your tax return much smoother.

Reference

[3] GOV.UK. Self Assessment tax returns: Deadlines. Available at: https://www.gov.uk/self-assessment-tax-returns/deadlines