What is a UK self-employed registration number?
Your Unique Taxpayer Reference (UTR), National Insurance number, and self-employed registration explained simply.
Short answer: In the UK, your 'self-employed registration number' is your 10-digit UTR (Unique Taxpayer Reference). You receive this from HMRC when you register for Self Assessment. Matthew registers you with HMRC, gets your UTR, and files your annual returns accurately.
Key points
- Your 10-digit UTR is your official Self Assessment registration number.
- Your National Insurance number (e.g. QQ 12 34 56 A) is completely separate.
- You must register with HMRC by 5 October following the end of the tax year you started working.
- Keep your UTR secure and only share it with HMRC and your authorised tax agent.
UTR vs National Insurance number
People often ask for a 'self-employed number'. In the UK, there are two key numbers:
1. UTR (Unique Taxpayer Reference): A 10-digit number that HMRC assigns to you for your tax returns.
2. National Insurance (NI) number: An 8-character letter and number code used for social security and state pension records.
Working cross-border or moving abroad
If you work as a sole trader or contractor while spending time between the UK and abroad, you still use your UTR to file your annual tax returns.
Matthew sets up your HMRC registration and files your annual self-employment accounts on time.
Written and reviewed by Matthew S Manderson CTA ATT AMIT
Chartered Tax Adviser (CTA), Association of Taxation Technicians (ATT), Association of Malta International Taxation (AMIT). General guidance only; tax treatment depends on individual facts.