What is a UTR Number, and how to get it?

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Whether you’re new to the UK, a young person just entering the workplace, or an experienced professional only just becoming self-employed, you may have heard very little of the UTR number before.

No matter who you are, if you’re looking to be self-employed in the UK - from running your own business to working freelance, getting your own UTR number needs to be at the top of your to-do list. 

An acronym for Unique Taxpayer Reference Number, your UTR number in the UK is a 10 or 13-digit code that is absolutely required for you to fill in your self-assessment tax return each year.

With an average of 13% of the UK working population being self-employed for the last two decades1 and a total of 4.25 million people being self-employed in 20242, there are lots of people in the same boat as you.

The one group of people you don’t want to join, however, are the 1.1 million people receiving HMRC fines for missing their tax self-assessment deadline3 in 2024.

To file your self-assessment taxes, you need your UTR number. Whether you're self-employed, running a business, or part of a partnership, having this number is compulsory.

But how does it work, and how do you get one? Here’s everything you need to know about UTR numbers, including why they’re important, the fastest way to get one, and how they work when filing your taxes.

What is a UTR number?

The UTR number’s meaning is HMRC's method of identifying and linking self-employed people to their correct tax returns. It is needed to register for self-assessment and to file taxes.

As a code, your Unique Taxpayer Reference number is typically a 10-digit code, sometimes a 13 digit code4 , that is made up of string numbers with or without spaces that start or end with a K. and is issued directly by HMRC upon request. It is only ever issued once, and will be your unique number for UK self-employment tax filing for the rest of your life.

The format of a UTR number follows this pattern:

  • Start with a K (or nothing)
  • Ten, or sometimes thirteen random numbers in a row
  • End with a K (or nothing)
For example, a valid UTR number could look like this: K1234 56789. It could also look like this: 1234567890k.

Typically, it is best to remove any spaces before entering it into an online system - i.e. even if your UTR number shows a space in between the numbers on your official document, just enter it as one long code online.

For those with 13 digits, if HMRC is requesting a 10 digit code specifically, you should only include the last ten digits when entering it online. This is because the first three extra digits typically indicate the specific tax office you are with.

Even if your circumstances change, whether you move abroad, become employed and paid via PAYE, or get married, your UTR number is permanent and never changes.

The good news is that you only need to apply for it once, and then you’re done.

Who needs a UTR number?

Generally speaking, anyone who gets paid in any form that isn’t PAYE - where your employer deducts tax from your pay before you receive it - will need both a UTR number and to file self-assessment tax returns each year.

If you receive money via PAYE and other means, you will still need a UTR number to fill out self-assessment tax returns for any relevant payments.

The three main groups that absolutely need a UTR number are:

Self-employed individuals

If you're self-employed, whether running a small side business or working as a freelancer or contractor, getting your UTR number as soon as possible is critical. 

Since your income does not have tax automatically taken off by an employer, you’ll need to pay the tax yourself. 

More critical for good financial health than tracking credit scores, you’ll want to make sure that you have a UTR number ready, keep track of your expected tax as you earn, and remember to register for self-assessment and pay your income tax and national insurance contributions accurately.


All businesses, including limited companies, partnerships, and corporations, need a UTR number for tax purposes. 

This is because the business itself is a taxable entity, and it will need to file company tax returns, pay corporate taxes, and handle payroll taxes for employees.


Along with individual partners, business partnerships must also obtain a separate UTR number to file their tax returns and pay taxes due on the partnership's profits.

For those new to the UK, a UTR is the one thing you’ll need more than a new credit card or better bank account if you’re going to fall into any of the above groups.

Not having a UTR number can lead to severe penalties from HMRC. In 2024 alone more than £100 million in fines were issued by HMRC5 for failing to register for self-assessment, missing tax return deadlines, and underpaying taxes due to improper filing.

Why don’t I need a UTR number when I’m employed?

When you are employed by a business, you are typically paid via PAYE (Pay-As-You-Earn)6, a system that essentially means the business you are employed by takes on the burden of sorting out your tax responsibilities.

This means that the business calculates your tax and national insurance based on your salary and then deducts them from each paycheck. 

At the end of the tax year, the business pays your tax for you - this is one of the many reasons every business or limited company needs its own UTR number, as it is filing tax both on company profits and corporate tax, as well as for all its employees under the PAYE system.

How to get your UTR number?

Having a UTR number is extremely important. It’s also super easy.

Getting your UTR number is possibly one of the most straightforward processes HMRC has created, and you can do so via the HMRC website7

Here's what you need to do:

  1. Register for Self Assessment: Visit the HMRC website7 and click on the "Register" link under the "Self Assessment" section. This will take you to the registration page.
  2. Complete the Registration Form: Throughout the form, you'll need to enter all your relevant details, such as your name, date of birth, national insurance number, and reasons for registering, i.e. self-employment, partnership or something else.
  3. Submit Your Registration: After carefully reviewing your information, submit your registration request. HMRC will then process your application and send you a UTR number by post within ten working days (21 days if you submitted a paper application).

If you already have a UTR number, you should be able to find it in your personal tax account8 or (if you have it) the HMRC App9. You should also be able to find it on any previous tax returns or any other documents from HMRC.

What documents are required?

To complete your UTR number registration, you'll need several documents ready and on hand to ensure you can add all your personal data correctly and prove your identity.

Here’s what you need:

  • Your National Insurance number
  • Proof of identity - typically your passport or driving license
  • Proof of your address, such as a utility bill or bank statement
  • Details of your self-employment, business, or other income sources

Common mistakes when getting your UTR number

While a straightforward process, getting your UTR number can involve some challenges or mistakes if rushed.

One of the first things to be careful of is providing incorrect personal information such as an inaccurate name, date of birth, National Insurance number or any other data.

This can lead to long delays in your application process, so it’s best to take your time and get it right on the first try.

Another thing to look out for is failing to disclose all sources of income, or submitting an incomplete application form, as both of these can also slow down your registration process. 

One of the most time-consuming mistakes to make is not having the required supporting documents, such as proof of identity and address, ready at hand. To make sure everything goes smoothly and quickly, come prepared and take your time to make sure everything is correct before you submit.

Your UTR number timeline

Once you've completed the registration process, you should receive your UTR number from HMRC within:

  • 10 working days for online applications
  • 21 days for paper applications sent by post

If you haven't received your UTR number within these timeframes, contact HMRC10 for assistance.

What is a UTR number used for?

At its core, your Unique Taxpayer Reference number is a tax number used for exactly what it says on the tin: identifying you for your tax returns.

Specifically, your UTR number’s primary function is for filing your annual self-assessment tax return.

It can also, however, be important as a source of identification Whenever you communicate with HMRC about taxes, as it allows them to quickly access your records and history.

While rare, other scenarios where your UTR number is needed could include:

  • Applying for business loans or financing
  • Registering as an employer and setting up a PAYE scheme
  • Claiming tax credits or certain benefits

Common challenges in obtaining a UTR number

Although getting your UTR number is generally straightforward, there are a couple of challenges you might face.

The first issue, though rare, is delays. These are most likely to occur during peak tax periods when HMRC has to deal with more applications than usual. Luckily, you can easily avoid this by applying for your UTR number well ahead of time.

As mentioned previously, any mistakes or incorrect details in your application form can lead to significant delays and processing errors, alongside time-consuming requests for clarification from HMRC. Once again, this challenge is easily overcome by taking your time with your first application, making sure to get it right.

If you’re new to the UK and don’t have all the documents you need, or if you just don’t understand the process, you may need to get additional support from HMRC. You can start by accessing extra guidance on the HMRC website11, and if needed you can contact HMRC via their phone helplines.

Frequently asked questions (FAQ)

How can I find my UTR number online?

If you already have a UTR number and can’t find it, try looking at previous tax returns, HMRC correspondence, or payslips. If these documents don’t have it, you can also contact HMRC directly12 and they can look it up using your details.

Can you have two or more UTR numbers?

No. Every UTR number is unique to one person, and every person (or business entity) has only one UTR number for life. Even if you have multiple income sources or businesses, your personal UTR number will always be the same when you file all your tax returns.

What should I do if I lose my UTR number?

If you've lost or misplaced your UTR number, contact HMRC immediately. They can provide you with your number again after verifying your identity.

How does a UTR number differ from other tax numbers?

Every tax number has a specific purpose. Your UTR is specifically to identify yourself when doing your self-assessment tax returns. 
Other tax numbers include:

  • Your National Insurance (NI) number, which is used for national insurance contributions and certain benefits.
  • Your VAT number, which is required for businesses registered for Value Added Tax (VAT).

Unlike these, your UTR number is specifically for reporting taxable income and filing tax returns.

How do I activate my UTR number?

Your UTR number does not technically need "activating", as it is “active” as soon as you register and receive it from HMRC. As soon as HMRC issues your UTR number, you can use it for self-assessments and tax filings.

Wrapping up - your next steps to getting your UTR

Whether you’re new to the UK or a long-time citizen just starting self-employment, getting your Unique Taxpayer Reference number should be a top priority.

This 10 or 13-digit code is your key to properly filing tax returns and avoiding pesky HMRC fines. All you need to do is head to the HMRC website and register for self-assessment13. Fill out a few forms, provide your personal information, and you’ll have your UTR number in no time.

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Sources: all third party information obtained from applicable website as of May 31, 2024

  1. https://www.statista.com/statistics/318208/uk-self-employment-rate/
  2. https://researchbriefings.files.parliament.uk/documents/CBP-9366/CBP-9366.pdf
  3. https://www.telegraph.co.uk/money/tax/income/hmrc-100m-fines-late-filing-tax-deadline-sunak-stealth-raid/
  4. https://design.tax.service.gov.uk/hmrc-design-patterns/unique-taxpayer-reference/
  5. https://www.telegraph.co.uk/money/tax/income/hmrc-100m-fines-late-filing-tax-deadline-sunak-stealth-raid/
  6. https://www.gov.uk/paye-online
  7. https://www.gov.uk/register-for-self-assessment
  8. https://www.gov.uk/personal-tax-account
  9. https://www.gov.uk/guidance/download-the-hmrc-app
  10. https://www.gov.uk/contact-hmrc
  11. https://www.gov.uk/government/organisations/hm-revenue-customs/contact/self-assessment
  12. https://www.gov.uk/find-utr-number
  13. https://www.gov.uk/register-for-self-assessment

This article is provided for general information purposes only and is not intended to address every aspect of the matters discussed herein. The information in this article is not intended as specific personal advice. The information in this article does not constitute legal, tax, regulatory or other professional advice from IDT Payment Services, Inc. and its affiliates (collectively, “IDT”), and should not be taken or used as such by any individual. IDT makes no representation, warranty or guaranty, whether express or implied, that the content in this article is current, accurate, or complete. You should obtain professional or other substantive advice before taking, or refraining from, any action on the basis of the information in this article.