How to Register as Self-Employed with HMRC

If you earn money from self-employment in the UK, you are legally required to register with HMRC. This applies whether you are freelancing, running a small business, selling goods online, or providing any kind of service for payment outside of PAYE employment.

You must register even if:

• Self-employment is your second job alongside PAYE employment
• You only earn a small amount — though if your total self-employed income is under £1,000 in a tax year, you may be covered by the trading allowance and not need to file a return
• You are working part-time or on a casual basis

Common examples of people who need to register include freelance designers, tutors, consultants, tradespeople, delivery drivers, content creators, and anyone selling products through their own website or marketplace.

If you are unsure whether your activity counts as self-employment, the key test is whether you are in business on your own account — controlling what work you do, how you do it, and when you do it. HMRC's employment status tool (CEST) can help you check.

You must register with HMRC by 5 October in the second tax year after you started trading. Since the UK tax year runs from 6 April to 5 April, this gives you a window — but waiting until the deadline is risky.

For example, if you started freelancing in July 2025 (during the 2025/26 tax year), your registration deadline is 5 October 2026. However, it is strongly recommended that you register as soon as you start trading. Here is why:

• Avoid penalties: Late registration can result in fines, especially if you owe tax and have not been making payments on account
• Get your UTR number sooner: Your Unique Taxpayer Reference can take several weeks to arrive, and you will need it to file your Self Assessment tax return
• Payments on account: HMRC may require advance payments towards next year's tax bill — the sooner you register, the sooner you can plan for these

There is no penalty for registering early, and it only takes around 10 minutes online. Registering promptly also means you start building a clean tax record from day one.

The fastest way to register is through the HMRC website. Here is exactly what to do:

1. Create a Government Gateway account — If you do not already have one, go to the HMRC sign-in page and select "Create sign in details." You will need your National Insurance number, a UK address, and either a UK passport or a payslip/P60 for identity verification.
2. Sign in and go to Self Assessment registration — Once logged in, navigate to "Register for Self Assessment" and select that you are registering as a sole trader (not a partnership or company).
3. Enter your personal details — Full name, date of birth, National Insurance number, and contact details.
4. Provide your business details — Your trading name (this can be your own name), the date you started self-employment, your business address, and the nature of your business (a brief description like "freelance graphic design" or "IT consulting").
5. Submit and wait for your UTR — HMRC will send your Unique Taxpayer Reference by post within 10 working days (or up to 21 days if you are abroad). You can also find it in your HMRC online account once processed.

You can also register by phone (0300 200 3310) or by post using form CWF1, but the online method is by far the quickest. Keep your Government Gateway user ID and password safe — you will need them every time you interact with HMRC online.

Your Unique Taxpayer Reference (UTR) is a 10-digit number that HMRC assigns to you when you register for Self Assessment. Think of it as your tax identity number — it stays with you for life, even if you stop being self-employed and restart later.

You will need your UTR to:

• File your annual Self Assessment tax return
• Set up payments to HMRC
• Communicate with HMRC about your tax affairs
• Verify your identity with some clients and agencies (certain organisations, especially in construction via CIS, will ask for your UTR before paying you)

Your UTR is different from your National Insurance number. While your NI number is used for employment and benefits, your UTR is specifically for Self Assessment and Corporation Tax. If you are a sole trader, you will have one UTR. If you later set up a limited company, the company will get its own separate UTR.

Keep your UTR somewhere secure and accessible. You can find it on previous tax returns, HMRC correspondence, or by logging into your HMRC online account. If you lose it, you can call HMRC's Self Assessment helpline on 0300 200 3310.

Once you have registered and received your UTR, several things happen:

You are enrolled in Self Assessment. This means HMRC expects you to file a Self Assessment tax return every year, covering the tax year from 6 April to 5 April. Even if you make a loss or earn below the personal allowance, you must still file a return while you are registered.

You become responsible for your own tax. Unlike PAYE employment where your employer deducts tax automatically, as a self-employed person you must calculate and pay your own Income Tax and National Insurance contributions. It is a good idea to set aside 25-30% of your profits for tax from the start.

You may be asked to make payments on account. If your tax bill is over £1,000 and less than 80% of your tax is collected at source (e.g. through PAYE), HMRC will ask you to make two advance payments — one on 31 January and one on 31 July — each equal to half of your previous year's tax bill.

You should start keeping records. From the date you register, you are legally required to keep accurate records of all income and expenses. HMRC can request to see these at any time, and you must retain them for at least five years after the 31 January submission deadline. Using invoicing software like OwnedWork makes this significantly easier.

Even though registration is straightforward, people still trip up. Here are the most common mistakes:

• Waiting too long to register. Some people trade for months or even years before registering. This can result in penalties and a large, unexpected tax bill. Register as soon as you start earning.
• Confusing self-employment with company formation. Registering as self-employed (sole trader) is different from setting up a limited company. If you are just starting out, sole trader status is usually simpler. Read our guide on sole trader vs limited company if you are unsure.
• Not keeping records from day one. Even before your UTR arrives, you should be tracking every invoice you send and every business expense you incur. Gaps in your records create problems at tax return time.
• Using the wrong business start date. Your start date is when you first started trading — not when you registered. If you did your first paid job in March but did not register until June, your start date is March.
• Forgetting to register for Class 2 National Insurance. This is usually handled automatically when you register for Self Assessment, but check your HMRC account to confirm. Class 2 NI contributions protect your entitlement to the State Pension and certain benefits.

Getting registration right from the start saves headaches later. If you have already missed the deadline, register immediately — the sooner you sort it, the smaller any penalty will be.