If you run a Limited Company, one piece of information you will need time and time again when dealing with HMRC is your Corporation Tax reference number. It is sometimes called your company’s Unique Taxpayer Reference or UTR, and it helps HMRC identify your business for all Corporation Tax matters.

In this guide, we explain exactly what the Corporation Tax reference number is, where to find it, how to recover it if you have lost it, and why it is so important to keep it safe.

What is a Corporation Tax reference number?

Your Corporation Tax reference number, or CTRN, is a unique 10-digit code issued by HMRC to every Limited Company in the UK. HMRC uses it to link your company to your Corporation Tax account, filings, and payments.

You will use this number whenever you:

• Registering for other taxes (e.g. registering for VAT or PAYE). 
• File your Company Tax Return (CT600).
• Pay Corporation Tax.
• Contact HMRC about your company tax account.
• Use HMRC online services.
• Working with an accountant or bookkeeper.

It is the key identifier for your company with HMRC and remains the same throughout the life of your business.

Paying Corporation Tax

When paying Corporation Tax, you will need a 17-character payment reference. This is based on your 10-digit Corporation Tax reference number, with extra characters identifying the accounting period. Always use the exact reference to avoid misallocated payments. You can pay online at HMRC Pay Corporation Tax.

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Is it the same as a personal UTR?

It’s easy to get confused, but your Corporation Tax Reference Number is not the same as your personal UTR. Your personal UTR is for your own income tax as an individual, while your CTRN is linked specifically to your Limited Company.

Even if you are the director of the company, the two numbers are separate. You use your personal UTR for things like Self Assessment, and your CTRN whenever you deal with Corporation Tax for your business. Keeping them distinct helps avoid mistakes when filing or making payments.

Comparing it to other official numbers

Limited Companies have several official numbers, here is a comparison table to help you understand what they are and how they’re different.

Where to find your Corporation Tax reference number

You will usually receive your CTRN within a few weeks of forming your Limited Company. HMRC sends a letter titled ‘Corporation Tax – Information for New Companies to your registered office address’. This letter contains your 10-digit corporation tax reference number.

If you have misplaced the letter, there are several other ways to locate your CTRN.

1. On letters from HMRC

Your CTRN is printed on most letters or notices from HMRC about Corporation Tax. Look for headings such as:

• Corporation Tax Reference.
• Company UTR.
• Unique Taxpayer Reference.

In these letters will often be reminders about filing deadlines, confirmation of registration, or payment requests. 

2. Through your accountant

If you use an accountant or accounting software like Crunch, your Corporation Tax reference number is often stored securely in your account. Your accountant can confirm it or retrieve it if necessary.

3. On your HMRC online account

If you have set up your company online with HMRC, your Corporation Tax reference number will appear in your account. Log in to HMRC Online Services, select Corporation Tax, and your CTRN will be displayed on your dashboard or in messages.

4. On company tax returns and payment confirmations

If you have filed a Company Tax Return previously, your CTRN will appear on the front page. It is also printed on payment reminders or statements from HMRC. It may appear as a UTR or Tax Reference Number.

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How to get a Corporation Tax reference number for a new company

You do not need to apply separately for a CTRN. HMRC issues it automatically after Companies House notifies them of your company formation. 

The steps are:

1. Form your Limited Company with Companies House.
   
   
2. Companies House shares your details with HMRC.
   
   
3. HMRC sends your CTRN to your registered office, usually within two to three weeks.
   
   
4. You then use the number to register for Corporation Tax online within three months of starting to trade.

Remember, your Corporation Tax reference number is confidential, and should be kept secure. This means never sharing your Company UTR publicly and only ever giving it to trusted parties, like HMRC or Crunch!

‍Lost your corporation tax reference number?

If you cannot find your CTRN, here are the steps you can take to locate it, and what to do if you still cannot find it.

Step 1: Check your online HMRC account

If you have set up an online Corporation Tax account, your CTRN will be displayed in the Corporation Tax section.

Step 2: Check old correspondence

Look for previous HMRC letters, reminders, or PDF statements. Search for headings such as Corporation Tax Reference or Unique Taxpayer Reference.

Step 3: Ask your accountant

Your accountant or bookkeeper will have the CTRN stored and can provide it safely.

Step 4: Contact HMRC

If you still cannot find your number, you can ask HMRC to send you the company UTR. You can use the online form at HMRC Find Lost UTR or call the Corporation Tax helpline (0300 200 3410).  

You will need to provide your company name, Company Registration Number, registered office address, and director details. HMRC will post the CTRN to your registered office. For security reasons, they do not provide it by email or over the phone.

Please bear in mind that this can take up a long 10-working days, so it’s important to keep it safe. Particularly around the times you’ll need it!
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Keeping your company UTR number safe

Your CTRN is important, so it’s worth keeping it somewhere you can easily find it. Try keeping your HMRC letters and scanning a copy, storing the number in your accounting software, or sharing it securely with your accountant. 

Organising your tax correspondence makes life easier, and having your CTRN to hand each year helps you avoid delays or penalties.
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How Crunch helps with Corporation Tax

We can handle all the tricky bits of Corporation Tax for you. From registering your company to filing your Company Tax Returns, and making sure HMRC gets your payments on time. 

If you’re ever unsure about deadlines, payments, or letters from HMRC, our UK-based experts explain everything clearly in plain English. We’ll also send friendly reminders before each filing, helping you stay on top of your tax without the stress.

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