The first step after starting as a sole trader is registering for Self Assessment with HMRC. It’s free, done online, and gets you the Unique Taxpayer Reference (UTR) you need to file your tax return.
When must you register?
Register by 5 October after the end of the tax year in which you started trading. The tax year runs from 6 April to 5 April. So if you started your business in January 2026 (the 2025/26 tax year), you must register by 5 October 2026.
If your self-employed income is £1,000 or less in the tax year, the trading allowance usually means you don’t need to register yet.
What you’ll need
About you:
- Full name, date of birth and address
- National Insurance number
- Email address and mobile number
- Details of any other income (for example a job or pension)
- ID for HMRC’s identity check, such as a passport, payslip or P60
About the business:
- The date you started trading
- Trading name (or your own name if you don’t have one)
- What the business does
- Business address and contact details
How to register, step by step
- Go to HMRC’s Register for Self Assessment page and choose to register as self-employed.
- Sign in with your Government Gateway or GOV.UK One Login details, or create an account using your email address.
- Set up two-step verification (a code by text or app) and keep your sign-in details safe.
- Confirm your identity using two of the options HMRC offers.
- Tell HMRC you’re a sole trader and give your business start date.
- Enter your personal and business details, check them and submit.
What happens next
HMRC will send your 10-digit UTR by post. Keep it safe: you need it to file your tax return and make payments. HMRC’s sign-in screens change from time to time, so the steps above may look slightly different. If you get stuck, check when to expect a reply on GOV.UK.
You don’t need to register separately for National Insurance. Since April 2024, Class 2 is treated as paid if your profits are £7,105 or more (2026/27), and Class 4 is worked out on your tax return. If your profits are lower, you can choose to pay voluntary Class 2 to protect your State Pension.
Next steps
- Start keeping digital records from day one. Making Tax Digital for Income Tax applies to sole traders with qualifying income over £50,000 from April 2026, dropping to £30,000 from April 2027.
- Read Self-employed? Tax and National Insurance explained to see what you’ll pay, or Employed, self-employed or limited company? if you’re weighing up your options.
Let us do it for you. Everyday Accountants can register you with HMRC as part of onboarding when you sign up with us for your tax returns. Get in touch for a free consultation and a no-obligation quote.
Information correct for the 2026/27 tax year at the time of writing.
Related guides: Do you need a UTR number?
Need help? See our tax services, or get in touch for a free, no-obligation chat.