Self-Employment Registration

If you start working for yourself in the UK, you must register as self-employed with HM Revenue & Customs. This triggers obligations to file Self Assessment tax returns and pay Income Tax and National Insurance on your profits. Understanding when and how to register is essential to avoid penalties and ensure you meet your obligations from day one.

What Counts as Self-Employment

You are self-employed if you run your own business and are responsible for its success or failure. Key indicators include: you have significant control over how, when, and where you work; you take financial risk; you provide your own equipment; you can hire others to do the work; you charge fixed fees rather than receiving a wage or salary; and you have multiple clients. HMRC uses a set of employment status tests (including the "control", "substitution", and "mutuality of obligation" tests) to distinguish self-employment from employment.

Registering with HMRC

You must register as self-employed with HMRC by 5 October following the end of the tax year in which you became self-employed. For example, if you started self-employment in the 2025–26 tax year, you must register by 5 October 2026. Registration is done online through your Government Gateway account. You will need your National Insurance number, personal details, and a description of your business activities.

UTR Number

When you register as self-employed, HMRC issues a Unique Taxpayer Reference (UTR) number. This 10-digit number is used for all correspondence with HMRC and must be included on your Self Assessment tax return. You will receive your UTR by post within 10 working days of registering. Keep it safe — you will need it every year to file your tax return.

Choosing an Accounting Date

Most self-employed people use the tax year (6 April to 5 April) as their accounting period. However, you can choose a different accounting date (such as 31 March or 31 December) if it better suits your business. Your chosen date affects the period covered by each Self Assessment return. Changing your accounting date later is possible but requires HMRC approval in some cases.

Class 2 National Insurance

Self-employed individuals with profits above the Small Profits Threshold (£6,725 for 2025–26) pay Class 2 NIC at £3.45 per week. Class 2 contributions count towards your State Pension and certain other benefits. If your profits are below the threshold, you can pay voluntary Class 2 contributions to protect your National Insurance record. From April 2026, Class 2 is expected to be abolished for most self-employed people, though the contribution record for pension purposes will be integrated with Class 4 contributions.

Deadlines

Missing the registration deadline results in an automatic penalty. The penalty for late registration starts at £100 and can increase if delays continue. Even if you miss the deadline, you should register as soon as possible to limit penalties and interest. If your self-employment income is below your Personal Allowance, you may not need to pay tax, but you must still register and file returns if HMRC requires them.