UTR number: What it is, who needs one and how to get yours

Published Friday 3 October 2025

Table of contents

• What is a UTR number?
• Who needs a UTR number?
• How to find an existing UTR number
• Before you apply for a UTR number
• How to apply for a UTR number for the first time
• Differences in the UTR registration process
• Using your UTR number
• Simplify your tax compliance with Xero
• FAQs on UTR numbers

Key takeaways

• Register for Self Assessment online to receive your UTR number automatically within 15 days, ensuring you apply well before tax deadlines to avoid failure-to-notify penalties.

• Locate your existing UTR number by logging into your HMRC personal tax account through Government Gateway, checking any HMRC correspondence, or using the official HMRC mobile app.

• Protect your UTR number by only sharing it with HMRC, your accountant, or authorised tax advisors, and never provide it to cold callers or unsolicited emails claiming to offer tax services.

• Gather all required information before applying, including your full name, date of birth, National Insurance number, current address, and business details if applicable, to speed up the registration process and prevent delays.

What is a UTR number?

A UTR number is a 10-digit identifier that HMRC assigns to track your tax account and match payments to bills.

HMRC gives you a UTR number automatically when you register for Self Assessment. You may have separate UTR numbers for personal and business taxes.

You need your UTR number to:

• Submit Self Assessment returns
• Pay tax bills online
• Work with accountants or bookkeepers
• Register for Construction Industry Scheme (CIS) refunds

Keep your UTR number safe – you will need it for all your self-employment tax tasks.

Who needs a UTR number?

You need a UTR number if you're:

• Self-employed or a sole trader
• Landlord with rental income
• Limited company director
• Member of a partnership or trust
• Charity filing returns
• Claiming CIS tax refunds in construction

If you need to file a Self Assessment tax return, you need a UTR number.

How to find an existing UTR number

If you have registered for Self Assessment, HMRC gives you a UTR number.

Find your existing UTR number using these methods:

Option 1: Government Gateway

• Log into your HMRC personal tax account
• Find your 10-digit UTR at the top of the page

Option 2: HMRC correspondence

• Check tax return reminders or payment notices
• Find your UTR printed on all HMRC letters

Option 3: HMRC mobile app

• Open the official HMRC app
• Go to your tax account summary

See HMRC’s guidance on how to find your UTR number.

If these don't work:

• Individuals: Call HMRC's Self Assessment helpline
• Limited companies: Request your Corporation Tax UTR online (you need your company name and registration number)
• HMRC phone lines are less busy between 8:30 am and 11 am

Before you apply for a UTR number

Gather the information you need before you start your Self Assessment registration. You'll need:

• Full name and date of birth
• Current address
• National Insurance number
• Contact phone number and email address

If you are registering as a business, you also need your business details, such as start date, business type, and address.

How to apply for a UTR number for the first time

Register for Self Assessment online by the deadline (usually 5 October after the tax year ends) to avoid failure-to-notify penalties.

3 ways to apply for your UTR number:

1. Register online and receive your UTR by post in 15 days
2. Call the HMRC Self Assessment helpline
3. Send a letter to HMRC (this is the slowest option)

Registering online lets you give all your information at once and get your UTR and activation code automatically.

Gather this information before you apply:

Personal details:

• Full name and date of birth
• Home address
• National Insurance number
• Phone number and email address

Business information (if applicable):

• Date you became self-employed
• Business type (sole trader, partnership, limited company)
• Business address
• Business phone number

Have these details ready to speed up your application and avoid delays.

Differences in the UTR registration process

The process for getting a UTR number depends on your business structure. Here is how to register for each type:

Sole trader

• Register for Self Assessment tax returns.
• You'll receive your UTR by post.

Register for Self Assessment on the HMRC website.

Partnerships

Register your partnership for filing returns. You'll then receive a UTR specific to the partnership.

Each partner must also register for Self Assessment and receive their own UTR number for personal tax returns. According to ACCA, this can be done by calling the helpline or completing form CWF1 either manually or online.

Register a partnership for Self Assessment on the HMRC website.

Companies

When you register your company with Companies House, you get a company UTR. Use this UTR when you file your corporation tax returns.

You need a separate UTR for your personal Self Assessment tax return.

Using your UTR number

Share your number with the right people to keep it secure.

Sharing your UTR number

Keep your UTR number secure – treat it like sensitive financial information.

Safe to share with:

• HMRC when filing returns or making payments
• Your accountant for Making Tax Digital registration and tax advice
• Authorised tax advisors handling your affairs

Never share with:

• Cold callers claiming to be from HMRC
• Unsolicited emails requesting tax information
• Anyone offering "tax refund services"

Only share your UTR number with trusted sources to keep your tax information safe.

Simplify your tax compliance with Xero

Keeping on top of your tax is easier with the right tools. Xero online accounting software helps you stay organised, so you can run your business with confidence.

With Xero, you can track income and expenses, prepare for Self Assessment, and share information with your accountant. Everything is in one secure place, so you can focus on your business.

Try Xero for free today to get started.

FAQs on UTR numbers

Find answers to common questions about UTR numbers below.

Can I submit a tax return online without a UTR number?

You need a UTR number to submit your tax return online. HMRC uses this number to match your return and payments to your tax account.

Double-check your UTR number before submitting returns to avoid these issues:

• HMRC penalties for filing without due care
• Delayed processing of your return
• Payment allocation errors

Double-check your UTR number before you submit your return to avoid complications.

What should I do if I've lost my UTR number?

If you have lost your UTR number, check any letters from HMRC or past tax returns. Your UTR number stays the same throughout your self-employment.

If you have a Government Gateway account, sign in and go to your personal tax account. Your UTR number is at the top of the page.

If you cannot find your UTR number, contact HMRC’s Self Assessment helpline.

How long does it take to get a UTR number?

HMRC sends your UTR number by post within 15 days of registering on their website. It may take longer if you live abroad.

Apply for your UTR number well before your next tax deadline to avoid penalties. Double-check your information to prevent delays.

See how long it takes HMRC to reply to questions.

How can I get my UTR number online?

Register for HMRC's online service. Wait for your UTR number to arrive by post (up to 15 days in the UK, or 21 days abroad). Sign up for Self Assessment with your UTR number. HMRC sends you an activation code about a week later. Use the code to activate your account and access Self Assessment