UTR Number - What It Is, How to Get One, and How to Find It

A UTR number - Unique Taxpayer Reference - is the 10-digit number HMRC assigns to every person registered for Self Assessment in the UK. If you are self-employed, you cannot file a tax return or register for CIS without it.

This guide explains what a UTR is, how to get one, how long it takes, and what to do if you have lost yours.

What is a UTR number?

UTR stands for Unique Taxpayer Reference. It is a 10-digit number - sometimes written as 1234 567 890 with spaces - that HMRC uses to identify you for Self Assessment. Every sole trader, self-employed person, partner in a partnership, and company director in the UK has one.

Your UTR is personal to you, not to your business. If you have been self-employed before, you may already have a UTR from that time. If this is your first time working for yourself, HMRC will issue a new one when you register.

Your UTR is not your National Insurance number. Your NI number (format: AB123456C) is your personal identifier across all government systems. Your UTR is only used for Self Assessment tax purposes.

How to get a UTR number

You get a UTR by registering as self-employed with HMRC. There is no way to apply for a UTR separately - it is issued automatically as part of the Self Assessment registration process.

Step-by-step registration

1. Set up a Government Gateway account at gov.uk if you do not already have one. You need a personal email address. HMRC emails your Government Gateway user ID immediately.
2. Register for Self Assessment. Log in and select "Register for Self Assessment as self-employed." Fill in your personal details, trade, and start date. The form takes about 10-15 minutes.
3. Wait for two letters from HMRC. First: an activation code for your Government Gateway account. Second: your UTR. Both arrive by post, usually within 10 working days. They arrive in separate envelopes.
4. Activate your Self Assessment account using the activation code. Once active, you can file returns, check your tax position, and manage payments online.

The full process typically takes 2-3 weeks from start to finish because of the postal steps. Register as soon as you start working for yourself - do not wait until the October deadline.

For the full registration walkthrough, see: How to Register as Self-Employed in the UK.

How long does it take to get a UTR number?

HMRC aims to send your UTR within 10 working days of receiving your registration. The letter arrives by post to your home address.

Once your registration is processed, you can sometimes find your UTR by logging into your Personal Tax Account at gov.uk - but the physical letter remains the primary delivery method.

If you have been waiting more than three weeks with no letter, call HMRC Self Assessment on 0300 200 3310. Have your National Insurance number and the approximate date you registered ready.

How to find your UTR number if you have lost it

Your UTR appears on several documents and can be retrieved online:

• Previous HMRC letters: Any Self Assessment correspondence - your original UTR notification, tax return notices, or payment reminders all carry it
• Your Personal Tax Account: Log in at gov.uk/personal-tax-account. Your UTR is on the summary page
• Previous tax returns: Your UTR is printed at the top of every SA100 self-assessment return
• Your accountant: If you use an accountant, they hold your UTR on file
• HMRC helpline: Call 0300 200 3310, verify your identity, and they can confirm it

What do you need your UTR for?

As a self-employed sole trader, you will need your UTR in several situations:

• Filing your Self Assessment return each year by 31 January
• Registering for CIS as a subcontractor - contractors verify your UTR with HMRC before paying you, which sets your deduction rate
• Communicating with HMRC about your tax position - always have it ready for calls or letters
• Working with an accountant - they need your UTR to access your HMRC records and file on your behalf

UTR numbers and CIS

If you work as a subcontractor in the construction industry, your UTR is especially important. Contractors must verify your UTR with HMRC before paying you under the Construction Industry Scheme (CIS). Your verified UTR is what triggers the lower 20% deduction rate.

Without a verified UTR, contractors are required to deduct 30% from your labour payments instead of 20%. That extra 10% goes to HMRC on account - you get it back at year end through Self Assessment, but it hurts your cash flow throughout the year.

Getting a UTR is not the same as CIS registration. Once you have your UTR, you must also separately register as a CIS subcontractor. See: CIS Explained for UK Builders and Tradesmen.

Can you work before you have your UTR?

Yes. You can start working for yourself before your UTR arrives - the registration deadline is 5 October following the end of the tax year, not the day you start work. However:

• If you work under CIS, contractors must deduct 30% from your labour payments until your UTR is verified. Register early to reduce this to 20%.
• You are still legally required to record and report all income from day one, UTR or not.

Frequently asked questions

What is a UTR number?

A UTR (Unique Taxpayer Reference) is a 10-digit number HMRC assigns when you register for Self Assessment in the UK. It identifies you as a self-employed person for tax purposes and is required to file your annual tax return.

How do I get a UTR number?

Register as self-employed with HMRC via gov.uk. Set up a Government Gateway account, complete the Self Assessment registration form, and HMRC posts your UTR within 10 working days. You cannot apply for a UTR separately - it is issued automatically as part of registration.

How long does it take to get a UTR number?

HMRC aims to post your UTR within 10 working days of receiving your registration. Allow 2-3 weeks from completing registration to receiving the letter. If it has been more than three weeks, call HMRC on 0300 200 3310.

How do I find my UTR number?

Check any previous HMRC Self Assessment letters, log into your Personal Tax Account at gov.uk (your UTR is on the summary page), or look at the top of any previous tax return. Your accountant will also have it on file. As a last resort, call HMRC on 0300 200 3310.

Is a UTR the same as a National Insurance number?

No. Your National Insurance number (format: AB123456C) is your personal identifier used across all government systems including PAYE, benefits, and state pension. Your UTR (10 digits) is only used for Self Assessment. You need both when registering as self-employed.

Do I need a UTR to work as a CIS subcontractor?

Yes. Contractors verify your UTR with HMRC before paying you under CIS. Without a verified UTR, they must deduct 30% from your labour payments. Register as self-employed to get your UTR, then separately register as a CIS subcontractor to reduce the deduction rate to 20%.