UTR Number Guide

Can't Find Your UTR Number? A Simple Guide to Finding or Getting One

Published: 24 August 2025
6 min read

UTR Number

10-Digit Reference

Your Unique Taxpayer Reference never changes - it's yours for life!

Filing your Self Assessment tax return can be stressful enough without the added panic of not being able to find your UTR number. Don't worry - this guide will help you find it or get a new one.

A professional woman is sorting through tax documents, highlighting her role in tax preparation and analysis in a contemporary office setting.

What is a UTR Number?

Your UTR, or Unique Taxpayer Reference, is a 10-digit number that HMRC uses to identify you for tax purposes. You need it to file your Self Assessment tax return and manage your tax affairs.

Good news: Like your National Insurance number, your UTR number never changes. Once HMRC issues one to you, it's yours for life. If you had one in the past, even years ago, it's still the same one.

I've Had a UTR Number Before, But I Can't Find It

If you've registered for Self Assessment in the past, your UTR number is hiding in plain sight. Here are the most common places to find it:

1

Check Your HMRC Paperwork

Have a dig through your files for any previous correspondence from HMRC. Your UTR number is printed on most documents they send regarding your personal tax, including:

  • Statements of account
  • Payment reminders
  • The initial letter telling you to complete a tax return
  • Your SA250 or "Welcome to Self Assessment" letter
2

Look at an Old Tax Return

If you have a copy of a tax return you've submitted in a previous year, your UTR will be clearly displayed on it, usually in the top right-hand corner.

3

Review Correspondence from Previous Accountants

If you used an accountant in the past, they would have used your UTR to file your returns. Check through any old emails, letters, or invoices they sent you. They often include the UTR as a reference, especially on correspondence about your tax bill.

4

Log in to Your HMRC Online Account

This is often the quickest and easiest method. If you have a Government Gateway account (your HMRC personal tax account), you can find your UTR there.

  1. 1. Log in to your HMRC online account
  2. 2. Once logged in, head to the Self Assessment section
  3. 3. Your UTR is usually displayed prominently on the dashboard
Click here to Login
5

Don't Have an Online Account? Create One!

If you've never set one up, now is a great time. By creating a personal tax account, you can easily view your tax information, including your UTR, once your identity is verified.

Create HMRC account
6

Call the HMRC Self Assessment Helpline

You can call HMRC and ask them to post your UTR to you. For security reasons, they will not tell you your UTR over the phone. They will only send it by post to the address they have on file.

Outside UK:

+44 1582 487594
7

Use the HMRC Webchat

Similar to the phone line, you can chat with an HMRC advisor online. Again, they will not give you the UTR in the chat but will happily post it to your registered address.

Click here to chat with HMRC

I've Never Had a UTR Number Before

If you've never filed a Self Assessment tax return, it's likely you don't have a UTR number yet. This means you need to register for Self Assessment with HMRC. Here's how you can do it:

1

Register for Self Assessment Online

The most straightforward way is to register online through the GOV.UK website. The system will guide you through a series of questions to determine your circumstances (e.g., self-employed, director, etc.) and get you registered.

Register for Self Assessment on GOV.UK
2

Chat with an HMRC Advisor Online

If you find the online forms confusing or you're unsure which options to choose, you can use HMRC's webchat service. An advisor can walk you through the process or help register you directly after asking a series of questions.

Click here to chat with HMRC
3

Call the HMRC Helpline

You can also register by calling the Self Assessment helpline. While some advisors may encourage you to use the online service, if you explain that you are struggling, they should be able to register you over the phone.

Outside UK:

+44 1582 487594

Important: Once you've registered, HMRC will post your UTR number to you. This can take a couple of weeks, so be sure to register well before the tax return deadline!

Still Struggling? Let Us Help

We know that dealing with tax admin can be a headache. If you're still stuck finding your UTR or daunted by the registration process, Taxwise Accountancy is here to help.

  • We can assist you in liaising with HMRC to find your existing UTR
  • We offer free Self Assessment registration for UK taxpayers
  • Let us handle the paperwork so you can focus on what you do best

Quick Summary: Finding Your UTR Number

UTR is a 10-digit number that never changes

Check HMRC letters, SA250, tax returns

Log into Government Gateway account

HMRC can post it (2 weeks delivery time)

Never had one? Register for Self Assessment

Taxwise offers free registration service