Sole trader starter guide

Register as self-employed with HMRC

A clear, step-by-step guide to Self Assessment registration, your Unique Taxpayer Reference and the records to organise from day one.

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Starting out as a sole trader can feel confusing. However, the registration process is easier when you know what HMRC needs and what happens next. This guide explains the main steps in plain English.

Who should register?

You normally need to register for Self Assessment if your gross self-employed income is more than £1,000 in a tax year. Different rules can apply in some circumstances.

What is a UTR?

Your Unique Taxpayer Reference is a 10-digit number. HMRC issues it after registration and uses it to identify your tax record.

What is the deadline?

You normally tell HMRC by 5 October after the end of the tax year in which you needed to complete a return.

Important: Register through the official GOV.UK service. Be cautious of websites that look official but charge simply to redirect you.

How to register as a sole trader for Self Assessment

Check whether you need to register

Review your self-employed income for the tax year. The tax year runs from 6 April to 5 April. If you are unsure, use HMRC’s official checking service before you begin.

Gather your details

Have your National Insurance number, contact details, business name, business address, start date and a short description of your work ready.

Create or use your Government Gateway account

You may need a Government Gateway user ID. Store the details securely because you will need them to access HMRC online services.

Complete the HMRC registration

Choose the route for a sole trader and answer the questions carefully. Check your start date and contact details before submitting the form.

Wait for your UTR

HMRC usually sends the UTR after registration. Keep it private and store the letter safely. You may need it when dealing with HMRC or appointing an authorised agent.

What information do you need?

Your full legal name and date of birth
Your National Insurance number
Your home and business contact details
The date your self-employment began
Your trading name, if you use one
A clear description of your business activity

What happens after registration?

Registration is only the beginning. You should keep reliable records of your sales, business costs, invoices and receipts. Good records help you understand your profit and prepare accurate year-end figures. They also reduce last-minute pressure.

It is sensible to use a separate bank account for business activity, even when it is not legally required. In addition, save digital copies of important documents and review your bookkeeping regularly.

Common registration mistakes

Using the wrong start date

Use the date your self-employed activity actually began, rather than the date you decided to create a business.

Registering twice

If you already have a UTR, you may need to reactivate Self Assessment instead of creating another record.

Waiting too long

Leaving registration until the deadline can delay access and create unnecessary pressure.

Already registered but cannot find your UTR?

Check previous HMRC letters and your Personal Tax Account. Your UTR is normally 10 digits. Do not post it publicly or send it through an insecure channel.

Records every new sole trader should organise

Start with a simple system. Keep sales invoices, purchase receipts, bank records, mileage information where relevant, and evidence for business costs. Then reconcile the records regularly. This makes year-end accounts preparation much smoother.

Frequently asked questions

Can I start trading before I register?

You can normally begin trading before registration. However, you must tell HMRC by the applicable deadline if you need to complete Self Assessment.

Do I need to register if I earn less than £1,000?

You may not need to register when your gross trading income is £1,000 or less. However, exceptions and voluntary registration can apply, so check the official HMRC guidance.

Can I be employed and self-employed?

Yes. Many people have PAYE employment and separate self-employed income. Keep the two sets of records clear.

How long does a UTR take to arrive?

Delivery times can vary. HMRC provides an online tool that lets you check when to expect a reply.

What if I registered in the past?

You may need to reactivate your Self Assessment account rather than register again. Follow the route for people who have previously registered.

Start with organised financial records

Real Key Accountancy supports sole traders with bookkeeping, computerised accounting records and accounts preparation. We can help you build a clear record-keeping system from the beginning.

Speak to the team now

Information is general and may change. Always confirm registration requirements and deadlines through GOV.UK.

Need help registering? We can support you through the registration process and help you prepare the information HMRC requires. This is administrative support and record preparation, not individual tax advice or HMRC representation.