How Do I Find My Corporation Tax Reference Number?

Quick answer: Your corporation tax reference number is a 10-digit number (also called a company UTR) issued by HMRC. You can find it on any HMRC letter, in your HMRC online account, or by calling the HMRC Corporation Tax helpline on 0300 200 3410. It stays the same for the life of your company. Your 17-character corporation tax payment reference, however, changes every accounting period.

Key Takeaways

Most companies have at least four different tax reference numbers and mixing them up is one of the most common causes of delayed Corporation Tax payments. Before you send a single penny to HMRC, make sure you're using the right one.

Here's everything you need to know.

What is a Corporation Tax Reference Number?

Your corporation tax reference number - also called your company UTR (Unique Taxpayer Reference) or HMRC COTAX reference - is a 10-digit number assigned to your limited company by HMRC when it registers for Corporation Tax.

It looks like this: 1234567890

HMRC uses this number to identify your company for all Corporation Tax matters, including filing your Company Tax Return, making payments, and any correspondence. Think of it as your company's tax identity, permanent, unique, and assigned to you for the lifetime of the business.

One thing to clear up immediately: your corporation tax reference number is not the same as your Company Registration Number (CRN). Your CRN is issued by Companies House when you incorporate. HMRC issues your UTR separately, typically arriving by post within three weeks of your company being formed.

How Do I Find My Corporation Tax Reference Number?

There are four reliable ways to track it down.

1. Check any letter from HMRC

Your 10-digit UTR appears on every piece of correspondence HMRC sends you - notices to file, payment reminders, penalty notices. If you've ever had a letter from HMRC about Corporation Tax, the number will be right at the top.

2. Log in to your HMRC online account

Sign in to your HMRC Business Tax Account at gov.uk. Once you're in, navigate to the Corporation Tax section and your UTR will be displayed there.

3. Ask your accountant

If someone else handles your Corporation Tax return, they'll have your UTR on file. Without it, they wouldn't be able to file on your behalf. At Debitam we are trusted for over 26,000 businesses across the UK, keeping their records, including company tax reference numbers.

4. Request it from HMRC directly

Lost it entirely? You can request your Corporation Tax UTR online via HMRC's dedicated service and HMRC will send it to your registered office address. Alternatively, call the HMRC Corporation Tax helpline on 0300 200 3410 (Monday to Friday, 8am to 6pm). Have your company name, CRN, and registered office address ready. Note: HMRC advisers cannot give you your 17-character payment reference over the phone - only your UTR

What Is the 17-Character Corporation Tax Payment Reference Number?

This is where most people get confused - and where mistakes happen.

Your corporation tax payment reference is a separate 17-character code that you must use whenever you pay your Corporation Tax bill. Unlike your UTR, this reference changes every accounting period. Using last year's reference - especially if you've saved HMRC as a payee in your online banking - will delay your payment being allocated to the correct period.

The format looks like this: 1234567890A00101A

Here's how it breaks down:

According to GOV.UK, using the wrong corporation tax payment reference can delay your payment. HMRC may also allocate it to the wrong accounting period entirely — which creates a bigger administrative headache than most directors want to deal with.

Is My Corporation Tax Reference Number the Same Every Year?

Yes. Your 10-digit UTR stays the same for the entire life of your company. From your first year of trading to your last, that number doesn't change.

Your 17-character corporation tax payment reference is different every year. It updates each accounting period, with the period number incrementing by one (01, 02, 03, and so on). Always double-check this before making a payment.

Is Corporation Tax Reference the Same as My Company UTR?

Yes, your corporation tax reference number and your company UTR are the same 10-digit number. HMRC uses these terms interchangeably.

However, your company UTR is not the same as your personal UTR. If you also file a Self Assessment tax return as a director, HMRC assigns you a separate personal UTR for that purpose. The two are distinct and cannot be used in place of each other.

How Can I Find My Corporation Tax Reference Number Online?

Here's the step-by-step process for finding both your UTR and your payment reference through your HMRC online account:

To find your Corporation Tax UTR:

1. Sign in to your HMRC Business Tax Account at gov.uk
2. Use your Government Gateway user ID and password. See where to find your government gateway user ID and password here.
3. Navigate to the Corporation Tax section
4. Your 10-digit UTR will be displayed in your account details

To find your 17-character Corporation Tax payment reference:

1. Sign in to your HMRC Business Tax Account
2. Select 'View Corporation Tax statement'
3. Click 'Accounting periods'
4. Select the correct accounting period you are paying for
5. Your 17-character payment reference will be shown

If your company hasn't yet set up an HMRC Business Tax Account, you'll need to register via Government Gateway before you can access these details online.

UK Company Reference Numbers: A Quick Guide

Limited companies juggle several different reference numbers. Here's a summary so you never mix them up:

TL;DR on How do I find my corporation tax reference number

• Your corporation tax reference number is your 10-digit company UTR, issued by HMRC after incorporation
• Find it on HMRC letters, in your HMRC online account, via your accountant, or by requesting it from HMRC online
• It never changes for the life of your company
• Your 17-character payment reference is different - it changes every accounting period and must be updated each time you pay
• HMRC's helpline is 0300 200 3410 (Mon-Fri, 8am-6pm) - but they cannot provide your payment reference number over the phone

Let Debitam Handle This For You

Getting your corporation tax reference wrong is an easy mistake. Getting your Corporation Tax return wrong is a costly one, especially now that late filing penalties have increased and HMRC's free filing portal closed in April 2026.

Debitam handles your Corporation Tax return from start to finish. No hidden fees, no last-minute surprises, and a dedicated accountant who knows your numbers. We'll make sure you're using the right references, filing on time, and not paying a penny more than you owe.

Get in touch with Debitam today

Frequently Asked Questions about How do I find my corporation tax reference number

Where exactly is my corporation tax reference number on an HMRC letter?

Your 10-digit UTR appears at the top of any letter from HMRC relating to Corporation Tax, usually labelled "Tax Reference" or "Unique Taxpayer Reference." It will be on your notice to file a return, payment reminders, and any penalty notices.

What happens if I use the wrong corporation tax payment reference when paying HMRC?

According to GOV.UK, using the wrong 17-character payment reference can delay your payment being allocated to the correct accounting period. In some cases, it may be allocated to the wrong company entirely, creating a compliance issue that requires additional time and correspondence to resolve.

Can I find my corporation tax reference number through Companies House?

No. Companies House holds your Company Registration Number (CRN), not your HMRC Corporation Tax reference. Your UTR is held by HMRC and can only be accessed through HMRC correspondence, your HMRC online account, or by contacting HMRC directly.

What should I do if my company has never received a UTR from HMRC?

HMRC sends your 10-digit UTR to your registered office address within approximately three weeks of company formation. If it hasn't arrived, you can request it online via HMRC's official service, or call the Corporation Tax helpline on 0300 200 3410. You'll need your company name, CRN, and registered office address ready.

Is the corporation tax payment reference number the same as the COTAX reference?

These terms are sometimes used interchangeably, but there is a distinction. The COTAX reference broadly refers to HMRC's Corporation Tax system identifier for your company (your 10-digit UTR), while the corporation tax payment reference is the specific 17-character code used when making a payment for a particular accounting period.

How do I find my corporation tax reference if I've lost all my HMRC letters?

Log in to your HMRC Business Tax Account at gov.uk - your UTR will be displayed in the Corporation Tax section. If you haven't set up an online account, use HMRC's online UTR retrieval service or call 0300 200 3410. Your accountant will also have this number if they file on your behalf.

How Do I Find My Corporation Tax Reference Number? <H1> Quick answer: Your corporation tax reference number is a 10-digit number (also called a company UTR) issued by HMRC. You can find it on any HMRC letter, in your HMRC online account, or by calling the HMRC Corporation Tax helpline on 0300 200 34

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Audited content structure, identified optimization gaps, formulated metadata enhancements

Audited content structure, identified optimization gaps, formulated metadata enhancements

SEO/AEO Grade: B+ (86/100)

AI/AEO rankability: Strong. This will likely surface in Google AI Overviews and get cited by Perplexity/ChatGPT Search. The quick-answer box, Key Takeaways table, comparison table, and TL;DR are exactly the extraction-friendly formats these engines pull from. FAQ answers are mostly self-contained (good for schema). This is one of your stronger AEO structures - the gap is entirely in linking and E-E-A-T signals, not content structure.

What's working

• Quick-answer block right after H1 - ideal for featured snippet + AI Overview capture
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Fixes needed

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