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Tax Reference Guide

How to find your UTR number (Unique Taxpayer Reference)

2 minutes · Self Assessment · HMRC

Your UTR is a 10-digit number HMRC uses to identify your Self Assessment record. You need it to register for MTD for Income Tax and to connect Margin to your HMRC account.

What does a UTR look like?

A UTR is always exactly 10 digits. It is sometimes called your "tax reference" on older HMRC correspondence.

Example UTR
1234 567890
10 digits — sometimes shown with a space after the first digit

Where to find your UTR

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HMRC letters
Any Self Assessment letter from HMRC — including your activation code and annual tax return notices — shows your UTR at the top.
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Personal Tax Account
Log in at gov.uk/personal-tax-account. Under "Self Assessment" your UTR is listed on the overview screen.
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SA302 / Tax return
Your SA302 tax calculation and your Self Assessment return both print your UTR at the top of every page.
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HMRC app
In the HMRC mobile app, go to Self Assessment and your UTR is shown on the main screen.

How to find your UTR in your Personal Tax Account

  1. Go to gov.uk/personal-tax-account
  2. Sign in with your Government Gateway User ID and password
  3. Click on Self Assessment
  4. Your UTR is displayed on the Self Assessment overview page
Don't have online access set up?

Call HMRC's Self Assessment helpline on 0300 200 3310 (Monday to Friday, 8am to 6pm). Have your National Insurance number ready. HMRC can confirm your UTR over the phone.

I don't have a UTR yet — do I need to register for Self Assessment?

Yes. If you are self-employed, a sole trader, or a landlord with rental income, you need to register for Self Assessment to get a UTR. HMRC will then post your UTR to you.

How to register for Self Assessment

  1. Go to gov.uk/register-for-self-assessment
  2. Choose the registration type that applies to you (sole trader, landlord, or other)
  3. Complete the online form with your personal details
  4. HMRC will post your UTR to your home address within 10 working days (up to 21 days if you are abroad)
Register early for MTD for Income Tax

If your turnover or rental income exceeds the MTD threshold (£50,000 from April 2026 or £30,000 from April 2027), you must register for Self Assessment and enrol for MTD ITSA before your mandation date. Registering late can result in penalties.

Why does Margin need my UTR?

When connecting Margin to HMRC, your UTR identifies which Self Assessment record to link to. It is used alongside your National Insurance number to ensure quarterly updates are submitted to the correct taxpayer record. Margin stores your UTR locally and never shares it with third parties.

Common questions

Is my UTR the same as my National Insurance number?
No. Your UTR is a 10-digit tax reference specific to Self Assessment. Your National Insurance number (NINO) is in the format AB 12 34 56 C. You may need both when connecting Margin to HMRC.
Can I use Margin without a UTR?
You can use Margin for invoicing, expense tracking, and bookkeeping without a UTR. However, you'll need a UTR to connect to HMRC and submit MTD quarterly updates.
My UTR is 11 digits — is that correct?
Standard UTRs are 10 digits. Some correspondence shows a "K" suffix (e.g. 1234567890K) which is a check digit — the UTR itself is still the 10 digits before the letter.
How long does it take to get a UTR after registering?
HMRC posts UTRs within 10 working days in the UK (up to 21 days overseas). You can sometimes access it sooner through your Personal Tax Account online.

Ready to set up Margin with your HMRC account?

Once you have your UTR, connecting Margin to HMRC takes under 5 minutes.

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