How to Register as a Sole Trader (Step-by-Step UK Guide)

Becoming a sole trader is the simplest, cheapest way to start working for yourself in the UK — and registering is quick and free. This guide walks you through exactly how to do it, when you have to, and what happens once you’re registered.

Do you need to register?

You need to register as a sole trader (for Self Assessment) once you’ve earned more than £1,000 from self-employment in a tax year. That £1,000 is the trading allowance — below it, you generally don’t need to register at all.

You also need to register if you want to prove you’re self-employed (for example, to claim Tax-Free Childcare) or make voluntary Class 2 National Insurance payments.

The deadline

You must register by 5 October following the end of the tax year in which you started trading. So if you started your business in, say, June 2025 (the 2025/26 tax year, which ends 5 April 2026), you’d need to register by 5 October 2026.

Don’t leave it to the last minute — you need your registration sorted well before the 31 January Self Assessment deadline, and the paperwork takes a couple of weeks to arrive.

How to register: step by step

1. Go to GOV.UK and start the “Register for Self Assessment” process for the self-employed.
2. Create a Government Gateway account (or sign in if you already have one).
3. Enter your details — name, address, National Insurance number, the date you started trading, and what your business does.
4. Submit. That’s the registration done — it takes about 10 minutes.
5. Wait for your UTR. HMRC posts your Unique Taxpayer Reference (a 10-digit number) within about 10 working days. You’ll need it to file your tax return.
6. Activate your online account. A separate activation code arrives by post — use it to finish setting up your Self Assessment online account.

That’s it. Registration is free, and you’ve now told HMRC you’re self-employed.

What happens after you register

Once registered, you’re in the Self Assessment system. That means each year you’ll:

• Keep records of your income and expenses
• File a Self Assessment tax return by 31 January
• Pay any Income Tax and Class 4 National Insurance due on your profits

You don’t pay anything to be a sole trader — tax only applies to your profit (income minus allowable expenses), and only above the £12,570 personal allowance. Our sole trader tax return guide explains exactly how the tax works.

A few things to sort early

• Records. Start tracking income and expenses from day one — it makes your tax return painless and ensures you claim everything.
• A business name. Sole traders can simply trade under their own name, or pick a business name (with a few restrictions). You don’t register it anywhere.
• A separate bank account. Not legally required, but it keeps business and personal money apart and makes bookkeeping far easier.

Sole trader or limited company?

Registering as a sole trader is the right starting point for most people — it’s simple and low-cost. As your profits grow, a limited company can become more tax-efficient and protects you with limited liability. We cover the trade-offs in sole trader vs limited company.

If you’d rather have it all handled — registration, records and your tax return — that’s exactly what our sole trader accountants do, for a simple fixed fee. We’ll make sure you’re registered correctly and never miss a deadline.