Registering for Self Assessment
Lesson 4 of 12 in our free Side Hustles & Self-employment guide: a 5-minute money game with the key points below.
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Questions you'll answer
Mo started trading in the 2026/27 tax year (ends 5 April 2027). When must he register for Self Assessment?
Quick facts
- Fact: “You can register for Self Assessment for free on gov.uk.” — It's free. Anyone charging you just to 'register' you is either an accountant you chose or a Ronnie.
- Myth: “The UK tax year runs January to December.” — It runs 6 April to 5 April. Very British. Very confusing.
- Myth: “Having a PAYE job means you never need Self Assessment.” — Your job's tax is sorted by PAYE, but side-hustle income over £1,000 still needs its own return.
- Register through gov.uk and get a Unique Taxpayer Reference (UTR) → Real step. That's the real process. Your UTR is your Self Assessment ID.
- Pay a '£79 HMRC registration fee' via a text link → Ronnie nonsense. Registering is free. A text link asking for a fee = scam.
- Note the 5 October registration deadline in your calendar → Real step. Future-you says thanks.
- 'Send us your bank login so we can register you' → Ronnie nonsense. Nobody legit needs your bank login. Ever.