Sole trader registration

Register as self-employed with HMRC

How to register for Self Assessment as a sole trader, get your Unique Taxpayer Reference (UTR), and understand your National Insurance obligations.

UK-wide
Guide summary

If you earn over £1,000 from self-employment in a tax year, you must register with HMRC for Self Assessment by 5 October. You will get a Unique Taxpayer Reference (UTR) by post to file tax returns. You may also need to pay National Insurance contributions.

  • Register for Self Assessment if you earn over £1,000 from self-employment
  • Deadline to register is 5 October after your first tax year
  • HMRC will post your 10-digit UTR in 10-15 days (UK)
  • Use your UTR to file tax returns and pay tax
  • File paper returns by 31 October, online by 31 January
  • Pay any tax owed by 31 January
  • Late registration can lead to penalties
  • Self-employed pay Class 2 and Class 4 National Insurance
  • Keep records of your income and expenses
  • Contact HMRC if you need help with registration
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When you start working for yourself as a sole trader, you must register with HMRC for Self Assessment. This is how the government tracks your income and collects the tax you owe.

Registration is straightforward but you must do it by the deadline to avoid penalties. Once registered, you will receive a Unique Taxpayer Reference (UTR) - a 10-digit number that identifies you for tax purposes.

Do you need to register?

You must register for Self Assessment if you earned more than the trading allowance from self-employment. You may also want to register even if you earn less, to prove your self-employed status for mortgages or benefit claims.

What is a UTR?

Your Unique Taxpayer Reference is issued for life - it will not change even if your circumstances do. You will need it to file tax returns, access HMRC online services, and for some business transactions.

When will you receive your UTR?

HMRC sends your UTR by post for security reasons. They will never email it or give it over the phone. Allow time for delivery before your first tax return is due.

Registration deadlines

Missing the registration deadline can result in penalties, even if you do not owe any tax. Register early to ensure you receive your UTR in time to file your first tax return.

National Insurance for the self-employed

As a sole trader, you pay Class 2 and Class 4 National Insurance on your profits. Class 2 is a flat weekly amount that protects your State Pension entitlement. Class 4 is calculated as a percentage of your profits above certain thresholds.

Understanding these rates helps you budget for your tax bill and plan for retirement.

What happens after you register

Once you have registered and received your UTR:

  1. Set up your HMRC online account - You will receive an activation code separately (within 10 working days). Use this to access your online Self Assessment account.
  2. Keep records of income and expenses - You will need these to complete your tax return. Keep records for at least 5 years.
  3. File your tax return by 31 January - This is for the previous tax year (6 April to 5 April). For example, for 2024/25, file by 31 January 2026.
  4. Pay your tax bill by 31 January - You may also need to make payments on account (advance payments) by 31 July.

Common mistakes to avoid

  • Registering too late - You must register by 5 October following the end of your first tax year of trading, not by your first tax return deadline.
  • Waiting for your UTR to arrive - If it has been more than 10 working days (21 days if overseas), contact HMRC. Do not wait until your tax return is due.
  • Confusing UTR with Government Gateway ID - Your UTR is 10 digits and identifies your tax records. Your Government Gateway ID is 12 characters and is used to log in to HMRC services.
  • Not keeping records - HMRC can charge penalties of up to £3,000 per tax year for inadequate record-keeping.
  1. 1

    Check if you need to register

    If you earned more than £1,000 from self-employment in a tax year, you must register. Below £1,000, registration is optional but useful for proving self-employed status.

  2. 2

    Register online with HMRC

    Use the Government Gateway to register for Self Assessment. You will need your National Insurance number and personal details.

  3. 3

    Wait for your UTR to arrive

    Your UTR will be posted within 10 working days (UK) or 21 working days (overseas). Keep this number safe - you need it for all Self Assessment activity.

  4. 4

    Activate your online account

    An activation code will arrive separately. Use it within 28 days to set up your online Self Assessment account.

  5. 5

    Set up record-keeping

    Start tracking income and expenses from day one. Use accounting software or a spreadsheet to make tax returns easier.

TURNOVER £1,000

Trading allowance - you may not need to register

If your total self-employment income is £1,000 or less in the tax year, you do not need to register for Self Assessment or tell HMRC about this income.

Above threshold:

You must register for Self Assessment by 5 October following the end of the tax year you started trading.

Below threshold:

The trading allowance automatically applies. You have no tax liability and no need to file a return for this income alone.

Strategic considerations: You may still want to register even below the threshold to prove self-employed status for mortgages, benefit claims, or to pay voluntary Class 2 NI for State Pension credits.
Compliance timeline: Registration deadline is 5 October following your first tax year of trading
Trading allowance (GOV.UK) (opens in a new tab)