How to Register for Self Assessment: Step by Step

Registering for Self Assessment is the first step to managing your own tax. Here is the exact process.

Before You Start

You will need:

• Your National Insurance number
• Your personal details (name, address, date of birth)
• The date you started self-employment
• Your business address and contact details
• The type of business you run

Step 1: Create a Government Gateway Account

Go to GOV.UK and search for "Government Gateway." If you do not already have an account, create one. You will need an email address, a phone for verification, and a password.

Step 2: Register as Self-Employed

Once logged in, navigate to Self Assessment registration. Choose "I am registering as self-employed" (form CWF1 is completed online).

Enter your:

• Business start date
• Business name (or your own name if you are a sole trader)
• Business address
• Type of business activity
• Accounting date (usually 5 April for sole traders)

Step 3: Wait for Your UTR

HMRC will post your Unique Taxpayer Reference (UTR) to you within 10 working days. This is a 10-digit number you need to file your return.

Keep your UTR safe — you will use it every year.

Step 4: Enrol for Self Assessment Online

Once you have your UTR, go back to your Government Gateway account and enrol for the Self Assessment online service. You will need your UTR and National Insurance number.

HMRC will send an activation code by post (another 7-10 days). Enter this code to complete your enrolment.

Step 5: Start Keeping Records

You are now registered. Start recording your business income and expenses. Accounted makes this automatic with bank feeds and AI categorisation.

The Registration Deadline

Register by 5 October following the end of the tax year you need to file for. If you started self-employment in June 2026, register by 5 October 2027. However, registering earlier is always better — it gives you time to receive your UTR and set up your online account without rushing.

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