How to Register as Self-Employed in the UK - Step by Step

When you start working for yourself in the UK - whether as a plumber, electrician, builder, or any other trade - you need to register as self-employed with HMRC. This is how the government knows to expect a tax return from you each year.

It takes about 15 minutes online. This guide walks through exactly what you need to do, when to do it, and what comes next.

When do you need to register?

You must register as self-employed if you earn more than £1,000 from self-employment in a tax year (the £1,000 is the Trading Allowance). The tax year runs from 6 April to 5 April.

The deadline to register is 5 October following the end of the tax year in which you started trading. So if you started in the 2024/25 tax year (April 2024 to April 2025), you must register by 5 October 2025.

In practice, most tradesmen register as soon as they start taking on jobs - do not wait for the deadline. There is no penalty for registering early, but there are penalties for registering late.

What you need before you register

• Your National Insurance number - check an old payslip, P60, or your NI card if you have one
• Your personal details - name, date of birth, address, phone number
• Your business details - trade name (if different from your name), start date, type of work
• A personal email address - you will use this for your Government Gateway account

How to register as self-employed with HMRC

1. Go to gov.uk and search for "register for Self Assessment as self-employed" or go directly to gov.uk/register-for-self-assessment
2. Set up a Government Gateway account if you do not already have one. You will get a User ID by email immediately and an activation code by post within 7-10 days. You need the activation code to access the full service.
3. Complete the online registration form. Select "I am self-employed" and fill in your personal and business details. The process takes about 10-15 minutes.
4. Wait for your UTR. HMRC will send your Unique Taxpayer Reference (UTR) - a 10-digit number - by post within 10 working days. Keep it safe. You will use this number every year.
5. Activate your Self Assessment account using the code that arrives separately by post. Once activated, you can file returns and manage your tax online.

The whole process from registration to a fully active account typically takes 2-3 weeks due to the postal steps. Start early - do not leave it until October.

What happens after you register?

Once registered, HMRC expects you to file a Self Assessment tax return every year, even if you earn below the tax threshold. You will need to:

• Keep records of all your income and expenses throughout the year
• File your return online by 31 January each year
• Pay any tax owed by 31 January

For everything you need to know about the return itself - tax rates, what you can claim, and how Payments on Account work - read the Self Assessment guide for sole trader tradesmen.

Do you also need to register for VAT?

VAT registration is separate from Self Assessment registration. You must register for VAT if your taxable turnover exceeds £90,000 in any 12-month rolling period.

You can also register voluntarily below this threshold - which gives you the ability to reclaim VAT on tools, materials, and van costs. For most tradesmen just starting out, voluntary registration makes sense once you are spending significant amounts on materials.

See the full guide: VAT for Tradesmen in the UK.

Do you need a business bank account?

Not legally, but strongly recommended. Keeping your business income and expenses separate from your personal account makes your tax return significantly easier to complete accurately. Most sole traders open a basic business current account as soon as they register.

What about the Construction Industry Scheme (CIS)?

If you work as a subcontractor in the construction industry, you also need to register for CIS with HMRC. Under CIS, the contractor deducts tax at source (20% if you are registered, 30% if not) and pays it directly to HMRC on your behalf. You still file a Self Assessment return at the end of the year and claim back any overpayment.

Registering for CIS is separate from Self Assessment registration and is done through the same HMRC online account. See CIS Explained for UK Builders and Tradesmen.

Frequently asked questions

Can I start working before I register?

Yes - you have until 5 October following the end of the tax year to register. But registering early means you get your UTR faster, which you will need when filing your return. There is no advantage to waiting.

What if I was previously employed and I am switching to self-employment?

Your National Insurance number stays the same. Register through HMRC online exactly as above. If you had PAYE tax deducted from a previous employment in the same tax year, that will be factored into your Self Assessment return when you file.

I lost my NI number - what do I do?

Call the National Insurance Helpline on 0300 200 3500 or check a previous P60, payslip, or any letter from HMRC or DWP. You cannot register without it.

What is a UTR and when do I need it?

Your Unique Taxpayer Reference is the 10-digit number HMRC uses to identify you for Self Assessment. You need it to log in and file your annual return. You will also need it if you register for CIS as a subcontractor. Keep the letter it arrives in somewhere safe. For a full explanation of what a UTR is and how to find a lost one, see the UTR number guide.

Is there a penalty for registering late?

HMRC can charge a late registration penalty based on the amount of tax you owe. In practice, the bigger risk is that late registration triggers late filing penalties on top - since your return will also be late if you register after the deadline. Register as soon as you start trading to avoid both.