How to Register for Self-Employment
A simple guide to registering as a sole trader with HMRC, what to watch for in the post, and the turnover thresholds you need to keep an eye on.
When and why to register
If you're trading on your own account — freelancing, contracting, selling goods, or providing services — HMRC needs to know. You should register as a sole trader as soon as you start, and at the latest by 5 October following the end of the tax year in which you began trading.
Registering puts you into Self Assessment, the system you'll use each year to declare your income and pay any tax and Class 2/4 National Insurance due.
Watch your post for your UTR
After registering, HMRC will send you a letter — usually within 10 working days (longer if you're abroad) — containing your UTR (Unique Taxpayer Reference). This is a 10-digit number you'll need every time you file a tax return or contact HMRC.
Keep it somewhere safe. If you set up an online Self Assessment account, a separate activation code will follow in a second letter, so don't bin anything HMRC-branded until it's all set up.
Lost letters happen. If your UTR doesn't arrive within 3 weeks, contact HMRC's Self Assessment helpline — don't ignore it, as missing the registration deadline can lead to penalties.
Turnover over £30k? Think Making Tax Digital
If your self-employment turnover exceeds £30,000, you'll fall under Making Tax Digital (MTD) for Income Tax. That means keeping digital records and submitting quarterly updates to HMRC through compatible software.
Honestly? Even if you're under the threshold, we'd recommend setting up digital bookkeeping from day one. It saves time, reduces errors, and means you're already compliant the moment your turnover crosses the line.
Keep an eye on the £90k VAT threshold
You must register for VAT once your taxable turnover exceeds £90,000 in any rolling 12-month period. It's not the tax year — it's any 12 consecutive months. So checking turnover monthly is essential.
Missing the threshold can mean backdated VAT bills and penalties, so build a habit of reviewing your trailing 12-month sales every month-end.
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Common Questions
How do I register as self-employed with HMRC?
Register online via gov.uk/become-sole-trader/register-sole-trader. You'll need your National Insurance number and personal details. HMRC will then post you a UTR (Unique Taxpayer Reference) — usually within 10 working days — which you'll need to file your Self Assessment.
What should I look out for in the post after registering?
Watch for a letter from HMRC containing your UTR (Unique Taxpayer Reference). It's a 10-digit number you'll use for every tax return. Keep it safe — you'll also receive a separate activation code if you set up an online Self Assessment account.
Do I need Making Tax Digital as a sole trader?
If your self-employment turnover is over £30,000, you'll need to comply with Making Tax Digital for Income Tax. Even below that threshold, using MTD-compatible digital bookkeeping from day one makes life much easier when the rules apply to you.
When do I need to register for VAT?
You must register for VAT once your taxable turnover exceeds £90,000 in any rolling 12-month period (not just the tax year). Keep an eye on turnover monthly so you don't miss the threshold.
Need a hand getting set up?
Our Brentwood-based team helps sole traders register with HMRC, set up MTD-ready bookkeeping, and stay on top of VAT thresholds. Get in touch for a free call.