How to Register as a Sole Trader in the UK: A Step-by-Step Guide

Starting your own business is an exciting milestone. For many freelancers, gig economy workers, and small business owners in the UK, operating as a sole trader is the simplest and most popular business structure. But how exactly do you set it up? This guide walks you through the process.

What is a Sole Trader?

A sole trader is a self-employed person who owns and runs their business as an individual. Legally, there is no distinction between you and your business. You get to keep all your business's profits after tax, but you are also personally responsible for any losses your business makes.

When Do You Need to Register?

You must register as a sole trader with HMRC if any of the following apply:

• You earned more than £1,000 from self-employment between 6 April and 5 April (the tax year). This is known as the Trading Allowance.
• You need to prove you are self-employed (for example, to claim Tax-Free Childcare).
• You want to make voluntary Class 2 National Insurance payments to help qualify for benefits.

The Deadline: You must register by 5 October in your business's second tax year. For example, if you started your business in June 2025 (the 2025/2026 tax year), you must register by 5 October 2026.

Step 1: Get a National Insurance Number

Before you can register for taxes, you need a National Insurance (NI) number. If you were born in the UK, you should have received one automatically at age 16. If you don't have one, you'll need to apply for one through the gov.uk website.

Step 2: Register for Self Assessment

To register as a sole trader, you actually register for Self Assessment with HMRC. This is the system HMRC uses to collect Income Tax.

Go to the gov.uk website and search for "Register for Self Assessment". You will need to create a Government Gateway user ID and password if you don't already have one.

You will need to provide:

• Your National Insurance number
• Your personal details (name, address, date of birth)
• The date your self-employment started
• The nature of your business

Step 3: Receive Your UTR Number

After you register, HMRC will send you a Unique Taxpayer Reference (UTR) number by post. This usually takes about 10 days (or 21 days if you are abroad). Keep this 10-digit number safe; you will need it every time you contact HMRC or file your tax return.

Step 4: Set Up Record Keeping

As a sole trader, you are legally required to keep records of your business income and expenses. You don't need to send these to HMRC with your tax return, but you must keep them for at least 5 years after the 31 January submission deadline, in case HMRC asks to check them.

Consider opening a separate business bank account. While not legally required for sole traders, it makes separating personal and business finances much easier.

Step 5: File Your Tax Return Annually

Once registered, you must file a Self Assessment tax return every year, even if you made a loss or didn't owe any tax. The deadline for filing online and paying your tax bill is 31 January following the end of the tax year.