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A UTR is a 10-digit number that HMRC uses to uniquely identify you for tax obligations and purposes. If you’ve registered for a UTR code, signed up for a Self Assessment tax return, or registered your limited company with Companies House, you will receive your UTR code in the post from HMRC within 10 working days (21 days if you’re abroad). In this article, we will cover all you need to know about UTR numbers.

Who needs a UTR number?

Anyone who is required to file a Self Assessment tax return will need a UTR number. Some examples would be:

  • Self-employed
  • Limited company director & shareholder
  • Construction workers
  • Landlords
  • Side hustlers (including eBay sellers and Etsy)
  • Freelancers & contractors
  • Charities/trusts
  • Partners

If you’re a construction worker and you want to register for the Construction Industry Scheme (CIS) tax refund, you’ll have to provide your UTR number as it’s HMRC’s way of identifying you.

Why is a UTR number required?

A UTR number is a 10-digit unique number for each taxpayer in the UK. Your unique number is required to file your Self Assessment tax return, so it’s required for all self-employed, freelancers, limited company owners and directors, and shareholders/partners. You’ll receive your UTR when you set up a new limited company, register as self-employed, or register for Self Assessment.

Not only is it required for a valid submission of your Self Assessment, but it’s necessary for Construction Industry Scheme (CIS) tax refund registration, and can also be important when you’re working with an accountant or financial advisor. 

How can I get my UTR number?

The simplest way to get your UTR number for the first time is to register for Self Assessment. As you have to provide other information to do this, it means you can just provide the information once, rather than get your first UTR number and then again when you’re registering for Self Assessment. If you’ve started your own limited company, you can get your first business UTR number when you register your business with Companies House.

You’ll then receive a letter with your activation code for you to go online and activate your UTR number.

An alternative option to get your UTR number is to call HMRC or write them a letter to request your UTR number.

What information is needed to register for a UTR number?

When you first tell HMRC about your business, notify them that you’re self-employed, or register for your tax return, you’ll automatically be registered for a UTR number. You’ll be required to register for your UTR number within a maximum of three months of opening your business.

You’ll be sent your activation code for your UTR number within 10 working days of registering, and you’ll then have 28 days to activate your online tax account before your code will expire.

You’ll need to know certain information to provide when you’re registering for your UTR number:

  • Some simple details such as your name, your date of birth, and your address
  • Your national insurance number (NI number)
  • A mobile number and email address
  • Your self-employment start date
  • Business type
  • Your business address and business number

Where can I find my UTR number?

Your HMRC UTR number can be found in a number of locations:

  • Your HMRC Personal Tax Account
  • The HMRC app
  • On a previous tax return
  • Other documents from HMRC such as your original limited company registration letter, a notice for you to file your tax return or payment reminders.

How can I get my UTR number online?

There are just five steps to getting your UTR number online:

  1. First, you’ll need to register for HMRC’s services online.
  2. You’ll then need to wait up to 10 days in the UK (21 if you’re abroad) for your UTR to be sent to you in the post.
  3. If you’ve now got your UTR number, sign up for your Self Assessment tax return.
  4. You’ll then need to wait another week for your activation code to arrive in the post.
  5. Once you’ve got your activation code, use it to activate your account so you can access Self Assessment.

How can I get my UTR number by post?

There are just three steps to getting your UTR number over the phone:

  1. Write a letter to HMRC asking them to provide you with a UTR number.
  2. You should receive a return letter requesting further details from you.
  3. Provide all the information that HMRC has requested and send it back. You should then receive your UTR number by post shortly after.

How can I get my UTR number over the phone?

There are just three steps to getting your UTR number over the phone:

  1. Ensure you have all of the details listed in the ‘What information is needed to register for a UTR number?’ section of this article to hand before calling, to avoid rushing around to get the information together while on the call.
  2. Give HMRC’s Self Assessment helpline a call and ask for your UTR number.

Note: They might ask you to apply for this online.

  1. You’ll then receive your UTR number by post within 10 working days (21 if you’re abroad).

Will my UTR number ever change?

After a personal or business UTR number has been issued to you, this cannot be changed. It’s unique to everyone to allow HMRC to identify you or your company for tracking tax bills and any payments that you’re responsible for.

If you were to de-register from being self-employed, go back to employment, and then become self-employed again, you’d be issued with the exact same UTR as you has when you were first self-employed.

What to do if you’ve lost your UTR number?

The first steps would be to check if you can access your HMRC personal tax account to find it, or search through any HMRC letters as they may be printed on other documentation. If all else fails and it’s well and truly lost, then you can request your UTR number via the HMRC Self Assessment helpline. You’ll most likely be asked to confirm some information, such as your national insurance number or personal details. They’ll then post it out to you by letter within 10 working days.

If you have a registered limited company and have lost your Corporation tax UTR number, you can request this online, and the letter will be sent to the address you have registered with Companies House.

In conclusion, if you’ve lost yours, don’t worry, you’ll be able to get a new copy confirming your unique number. What you’ll want to avoid is going to file your Self Assessment at the last minute and finding you’ve lost your UTR number and missing your filing deadline, as this can result in a fine from HMRC.

Is a UTR number the same as a tax reference code?

Your UTR number and tax reference code are different.

A UTR number is 10 numbers that identify yourself or your business if you’re self-employed or own your own company. If you’ve always been employed, you’ve probably never had nor needed a UTR number.

A tax reference code is different as it’s a selection of numbers and letters so HMRC can identify any conditions that may affect your tax situation, as well as the tax-free personal allowance that you qualify for.

Will I need my UTR number to get paid?

If you’re self-employed or own your own business, then yes. If you’re self-employed and working your job without your UTR number, you could end up in problems with HMRC as that’d mean you haven’t properly registered for a Self Assessment tax return. Technically if your earnings are taxed through the PAYE system, you don’t earn over £100,000 a year and you aren’t trying to claim a tax refund, it’s not 100% necessary to have a UTR number. But, you might still need to submit a Self Assessment if you aren’t self-employed, which you’d need your UTR for, resulting in trouble with HMRC, so it’s always worth checking.

We’d recommend that you get in touch with an accountant to clarify if you need a UTR number to get paid. All of our Crunch paid subscriptions include unlimited access to an accountant so our clients can ask those very important questions to avoid getting on HMRC’s bad side. But, if you aren’t on a Crunch paid plan, you can still get in touch with a real qualified accountant through our ‘Ask an Accountant’ service.

Can you share a UTR number?

UTR numbers are important for HMRC to identify you. There have been previous cases where UTRs have been stolen and used in scams. You shouldn’t need to share your UTR with anyone besides your accountant/financial advisor, HMRC, or if you’re registered for CIS, then the person in charge of paying you.

Do construction employers ask for a UTR number and why?

When working in construction, you’ll quite often be self-employed. When you’re self-employed, you should have your UTR number. You can’t register to complete your Self Assessment or sign up for the Construction Industry Scheme (CIS) without this number. CIS is where the scheme takes 20% off your self-employed construction worker pay, as payment in advance for the tax you’ll owe by the end of the tax year.

Having your UTR to hand is vital to make sure you’re signed up to CIS properly to pay your tax, so you can easily claim back anything owed to you.

If you decide not to register for CIS, you’ll be losing more of your pay to tax, as on CIS, you’ll pay 20% tax on your earnings. But, if you don’t register, you’ll have a higher tax deduction of 30% and you’ll still be required to file your tax return, which as we covered previously, failure to file your tax return can lead to a large fine, losing you even more of your hard-earned money.

CIS was originally introduced to try and crack down on ‘cash in hand’ work in the construction industry. It has been reported that often workers can end up overpaying on their taxes through this scheme, however, you’ll still get this back at the end of the tax year (5th of April of that year). If you’re self-employed, HMRC determines if you’re due a refund and if so, how much, based on your submitted Self Assessment.

If you’ve signed up for CIS, the person paying you is required to send your 20% advanced tax payment to HMRC, which is why they’ll ask for your UTR number when you begin your work.

What is the difference between a normal UTR number and a company UTR number?

Self-employed people will require a UTR number as well as a business. When you first register your business to Companies House, you’ll be sent your business UTR number. It should be the same as a personal UTR number, in that it’s a 10-digit number used to identify your company for tax purposes. Similarly to a personal UTR, a business UTR can be found on important documents received from HMRC to your business, such as a CT603 form (notice to complete your company tax return).

Note: A business UTR number is different from a company registration number (CRN).

Are you charged for having a UTR number?

No, there’s no cost for getting your UTR number, for the first time or even when you request a new letter showing your UTR number if you lost your original.

Is a UTR number on a P45?

In short, no it won’t be. You shouldn’t require a UTR number if you work for an employer as you should be a part of the PAYE system. You get a new P45 when you stop working for an employer and should have your NI number, a tax code, and a PAYE reference number, none of which are the same as a UTR number.

Getting started?

Are you starting your self-employed journey or registering your new business? Whether you're a sole trader or if you're trading as a limited company and you're in need of corporation tax filing support, our experts are on hand to help.

We have an array of helpful articles, calculators, and videos all designed to answer your finance and accounting questions when you’re starting out - we even have a handy business terms glossary, helping you to cut through the many abbreviations you're likely to come across as a business owner! We also have our company formation service for those starting a limited company, where our team will register your limited company on your behalf for just £10 for Crunch free clients, or included in your subscription for limited company pro, premium, and small business clients.

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Alexandra Moore
Content & communications specialist
Updated on
March 21, 2023

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