You've got it right — well done for checking. If you started freelancing in the 2025/26 tax year (6 April 2025 to 5 April 2026), you need to register by 5 October 2026. That's confirmed on GOV.UK. And yes, it's all done online: go to GOV.UK and search for "register for Self Assessment", then follow the sole trader route. The form itself takes about 15 to 20 minutes.
On the UTR: HMRC posts your Unique Taxpayer Reference to you after you register, which usually takes around 10 working days, though it can be slower at busy times. And good news on the invoicing question — you don't need to wait. You can start trading and invoicing clients straight away; registration is about notifying HMRC by the deadline, not getting permission to work.
A few things that tend to catch new freelancers out:
1. Leaving registration to the deadline. Do it as soon as you start trading and it's one less thing hanging over you.
2. Poor records. Keep every invoice, receipt and bank statement from day one — you'll thank yourself when the tax return is due.
3. Payments on account. Once your tax bill tops £1,000, HMRC asks for half of next year's bill in advance, so your first January payment can be around 1.5 times what you expected. Budget for it from the start.
4. National Insurance. Class 4 NI is collected through your tax return: 6% on profits between £12,570 and £50,270, and 2% on profits above that, for 2025/26 and 2026/27. Class 2 was abolished from April 2024, so there's no separate weekly bill for most people.
Once you're registered, your first tax return is due by 31 January following the end of the tax year you started in. Good luck with the freelance life!
Anna
