Who Needs to Register as a Sole Trader?
You need to register as self-employed with HMRC if you're earning money from self-employment — whether that's freelancing, running a small business, selling goods, or doing paid work outside of employment. It doesn't matter whether it's your main income or something you do alongside a regular job.
The threshold that triggers a legal obligation to register is earning more than £1,000 from self-employment in a tax year (6 April to 5 April). This is known as the trading allowance. If you earn less than £1,000, you don't need to register — though you can choose to if it's useful for your records or to build up National Insurance contributions.
If you're already employed and paying tax through PAYE, you still need to register separately for your self-employed income. HMRC doesn't automatically know about it.
The Registration Deadline
You must register with HMRC by 5 October following the end of the tax year in which you started trading. So if you started earning self-employed income in the 2025/26 tax year (which runs from 6 April 2025 to 5 April 2026), you have until 5 October 2026 to register.
That said, there's no benefit to waiting. Registering early means you'll receive your Unique Taxpayer Reference (UTR) sooner, which you'll need to file your tax return. It also means you won't accidentally miss the deadline if things get busy. Most people register as soon as they start trading — or even before.
Missing the deadline
If you miss the 5 October deadline, HMRC may charge a penalty. However, if you register late but before the 31 January Self Assessment filing deadline, penalties are often waived. Don't let fear of a late penalty stop you from registering — it's always better to register late than not at all.
What You'll Need Before You Start
The registration process takes around 10–15 minutes if you have everything to hand. Before you start, make sure you have:
- Your National Insurance number (on your NI card, payslip or P60)
- Your home address and contact details
- The date you started (or plan to start) trading
- A brief description of what your business does
- A rough estimate of your self-employed income for the current tax year
- A Government Gateway user ID and password (you can create one during registration)
How To Register: Step by Step
Go to the HMRC registration page
Visit gov.uk and search for "register as self-employed" or go directly to the Self Assessment registration service. You'll be asked to sign in with a Government Gateway account. If you don't have one, you can create one during the process — it takes about five minutes.
Tell HMRC you're self-employed
You'll be asked a series of questions about your situation. Select that you're registering as self-employed (sole trader). You'll need to confirm the date you started trading — this is the date you first received income from your business, not the date you had the idea.
Enter your personal details
You'll need your full name, date of birth, National Insurance number, home address and contact details. Make sure these match what HMRC already holds for you — discrepancies can cause delays.
Describe your business
You'll be asked for a brief description of what your business does and your trading name (if different from your own name). You'll also be asked for an estimate of your income for the current tax year — don't worry if you're not sure, you can give a rough figure.
Submit and wait for your UTR
Once you've submitted the form, HMRC will send your Unique Taxpayer Reference (UTR) by post within 10 working days. You'll also receive a letter with your Self Assessment activation code, which you'll need to complete your online account setup.
What Is a UTR and Why Does It Matter?
A Unique Taxpayer Reference (UTR) is a 10-digit number that HMRC uses to identify you for Self Assessment purposes. Think of it as your personal tax ID for self-employment. You'll need it every time you file a tax return, and some accountants and financial institutions will ask for it too.
HMRC sends your UTR by post, usually within 10 working days of registering. It arrives in a plain envelope — keep an eye out for it and don't throw it away. Once you have it, store it somewhere safe. You can also find it on any correspondence from HMRC, or by logging into your Government Gateway account.
If you've previously filed a Self Assessment tax return (for example, because you had rental income or investment income), you may already have a UTR. In that case, you just need to add self-employment to your existing account rather than registering from scratch.
What Happens After You Register?
Once you're registered, HMRC will expect you to file a Self Assessment tax return each year. The tax year runs from 6 April to 5 April, and the deadline for filing online is 31 January the following year. So for the 2025/26 tax year, your return is due by 31 January 2027.
You'll also need to keep records of your income and expenses throughout the year. This doesn't have to be complicated — a simple spreadsheet or a basic accounting app will do the job. The key is to keep receipts and records as you go, rather than trying to reconstruct everything in January.
If your turnover (total sales, before expenses) exceeds £90,000 in a 12-month period, you'll also need to register for VAT. This is a separate registration from your Self Assessment registration.
National Insurance as a Sole Trader
As a sole trader, you pay National Insurance contributions (NICs) on your self-employed profits. There are two classes to be aware of:
Class 2 NICs
A flat weekly rate (currently £3.45/week for 2025/26) paid if your profits are above the Small Profits Threshold (£12,570). From April 2024, Class 2 NICs are no longer collected separately — they're calculated through your Self Assessment return and treated as if paid, which protects your State Pension entitlement.
Class 4 NICs
Calculated as a percentage of your profits above the Lower Profits Limit. Currently 6% on profits between £12,570 and £50,270, and 2% on profits above that. These are calculated and paid through your Self Assessment return.
If your profits are below the Small Profits Threshold, you can choose to pay voluntary Class 2 NICs to protect your entitlement to the State Pension and certain benefits. This is worth considering if you're in the early stages of building your business and your income is low.
HMRC Registration Checklist
Download our free checklist so you have everything ready before you start the registration process.
Get the free checklistGo deeper
Follow the full registration pathway or pick up the Sole Trader Handbook for everything you need to know about running your business.
Disclaimer: This guide is for general information only and does not constitute legal or financial advice. Always check current HMRC guidance and seek professional advice where appropriate.