Note: MTD for Income Tax may apply to you. If your qualifying income exceeded £50,000 in 2024/25 you should already be using MTD (from 6 April 2026). Thresholds drop to £30,000 (from April 2027) and £20,000 (from April 2028). Check via the MTD for Income Tax Checker.
How do I register for UK Self Assessment as a new freelancer?
Register at gov.uk/register-for-self-assessment using your Government Gateway ID. Deadline is 5 October following the tax year you started freelancing. HMRC posts your UTR within 10-14 days. Then file online by 31 January of the following year.
Key takeaways
- Register by 5 October of the second tax year you're trading
- UTR arrives by post within 10-14 days
- First return covers everything since your start date
- Under £1,000 trading allowance = often no need to register
- Failure to Notify penalty applies if you register late
When registration is triggered
Registering for Self Assessment is the first thing you must do when you start earning self-employed income in the UK — and missing the 5 October deadline for the tax year in which you started can trigger a Failure to Notify penalty on top of any tax owed. This guide walks the actual registration route step-by-step, what you'll need to hand, and what HMRC sends back.
When registration is triggered
Register by 5 October following the end of the tax year in which you first became self-employed. If you started freelancing on 15 May 2025 (in the 2025/26 tax year), the deadline is 5 October 2026. Miss it and HMRC's Failure to Notify penalty applies — a percentage of the tax owed, dependent on whether the failure was deliberate or careless.
Registration is also required if you've been self-employed before, deregistered, and started again.
The registration route step-by-step
You register through GOV.UK using your Government Gateway ID (create one if you don't have it). Path: sign in → 'Get help with Self Assessment' → 'Register for Self Assessment (new self-employment)'. You'll be asked for: full name, address, date of birth, National Insurance number, and the date you started self-employment.
Process a few days, then HMRC posts you a UTR (Unique Taxpayer Reference) — a 10-digit number that stays with you for life. Without it you cannot file.
What HMRC sends and what to do with it
You'll receive: your UTR letter (keep it safe — you'll need it every January), a Government Gateway activation code for online services if you didn't already have one, and eventually a notice to file a Self Assessment return for the tax year of registration. The first return is due 31 January following the tax year end.
Worked example
You started freelancing 12 June 2025. That's within the 2025/26 tax year (6 April 2025 to 5 April 2026). Registration deadline: 5 October 2026. First Self Assessment return: covers 6 April 2025 to 5 April 2026, filed online by 31 January 2027. If total tax exceeds £1,000 that year, payments on account for 2026/27 also become due — first payment 31 January 2027, second 31 July 2027.
Reference table
| Question on registration form | What to enter | Note |
|---|---|---|
| Date started self-employment | Actual first-invoice date | Not date of first idea |
| Business description | One-line honest description | Freelance UX designer, consultant, etc. |
| Business address | Home OK for freelancers | Doesn't need to be commercial |
| NI number | Your existing NI number | Not a company number |
| Expected turnover | Best estimate | Purely informational |
Pre-registration checklist
- Government Gateway ID (create at gov.uk if new)
- National Insurance number
- Home address + postcode
- Rough business description
- Start date of self-employment
- Bank account for future tax payments (not required at registration, but useful next)
The online form takes 5-10 minutes. HMRC issues your UTR by post within about 10 working days. Digital-only issuance is being rolled out.
File as soon as possible. Failure to Notify penalties are lower if the failure was 'careless' and if you disclose voluntarily before HMRC contacts you.
The trading allowance means you don't need to register or file if your gross self-employed income is under £1,000 in the tax year — unless you're already registered for another reason.
You can only register once you've actually started self-employment. HMRC doesn't accept prospective registrations.
Yes — Self Assessment is only for self-employed sole traders. VAT and Corporation Tax have separate registrations.
Sources & official references
Related on FreelanceToolkit UK
This guide is general information based on UK rules for the 2025/26 tax year. It is not personal tax or legal advice. For decisions affecting your tax position or legal exposure, consult a qualified accountant or solicitor.