What Is a UTR Number?
When you set up a limited company in the UK, HMRC assigns your business a Unique Taxpayer Reference, commonly known as a UTR number. This 10-digit reference identifies your company for all tax purposes — and you will need it every time you file a company tax return, pay corporation tax, or contact HMRC about your company's tax affairs.
Understanding your UTR, where to find it, and when to use it is one of the first things to get right as a company director. This guide explains everything you need to know.
What Does a UTR Number Look Like?
A UTR number is a 10-digit number. On HMRC correspondence it may simply be labelled "tax reference." It appears as a single 10-digit string and is unique to your company.
Unlike your Company Registration Number (CRN) from Companies House, your UTR is not published on the public register. It is a private reference used only between your company and HMRC.
How a Limited Company Gets a UTR Number
Your company's UTR is assigned automatically when you register for corporation tax with HMRC. You do not apply for a UTR separately — it comes as part of the registration process.
Here is how the process works:
- Incorporate your company at Companies House. You will receive a Company Registration Number (CRN) at this point — but not yet a UTR.
- Register for corporation tax with HMRC. You must do this within three months of starting to trade. You can register online through the GOV.UK Business Tax Account service.
- Receive your UTR by post. HMRC sends the UTR to your company's registered address (as it appears at Companies House), typically within 15 days of registration. If your registered address is overseas, allow additional time.
When Must a Company Register for Corporation Tax?
HMRC requires every active limited company to register for corporation tax within three months of starting to trade. "Starting to trade" is broader than simply making sales — it includes:
- Buying stock or materials
- Renting or buying premises
- Employing staff
- Advertising your services
- Signing contracts
Company UTR vs Personal UTR
As a company director, you may have both a company UTR and a personal UTR. They are entirely separate and must never be confused.
| Reference | Who it is for | What it covers |
|---|---|---|
| Company UTR | Your limited company | Corporation tax, company tax returns (CT600) |
| Personal UTR | You as an individual | Self Assessment, income tax on dividends and salary |
Where to Find Your Company's UTR
Once HMRC has issued your UTR, you can locate it in several places.
On HMRC correspondence Check any letters from HMRC addressed to your company — filing notices, payment reminders, and registration confirmation letters all carry the UTR. It is typically displayed near the top of the letter.
On previous tax returns If your company has filed a CT600 before, the UTR appears at the top of every return.
Through HMRC Online Services Log in to your Business Tax Account on GOV.UK. Your UTR will be displayed alongside your company's tax records.
By requesting it from HMRC If you cannot find your UTR, you can request it online through the GOV.UK service. HMRC will send it to your company's registered address with Companies House.
For a step-by-step guide to locating your reference, see our guide to finding your company UTR.
Why Your UTR Is Required for Tax Filing
Your UTR is not just an administrative detail — it is essential for several key processes.
Filing your company tax return (CT600) Every company tax return submitted to HMRC must include the company's UTR. The submission is matched to your tax record using this reference. A wrong or missing UTR will cause the return to be rejected.
Paying corporation tax When you make a payment to HMRC via online banking or BACS, your UTR must be included as the payment reference. Without it, HMRC cannot allocate the payment to your account — you may receive late payment notices even if you have paid in full.
Contacting HMRC Any enquiry to HMRC about your company's tax — whether by phone or online — will require your UTR for identification.
Authorising a tax agent If you use an accountant to manage your corporation tax, they will need your UTR to be authorised to act on your behalf through HMRC Online Services.
For a complete overview of the filing process, read our guide to filing your company tax return.
UTR and Corporation Tax Deadlines
Once HMRC has your UTR on record, it will send a notice telling your company when its first company tax return (CT600) is due. The deadline for filing is typically 12 months after the end of your accounting period, with the corporation tax payment itself due 9 months and one day after the accounting period ends.
Missing these deadlines results in automatic penalties. Your company must file on time every year — even if it made no profit or was dormant during the period.
For a full breakdown of dates by year-end, see our guide to company tax return deadlines.
Frequently Asked Questions
Can I file my company tax return before I receive my UTR? No. You cannot submit a CT600 to HMRC without a valid UTR. If your filing deadline is approaching and your UTR has not arrived, contact HMRC's Corporation Tax helpline as soon as possible.
Is a UTR the same as a Company Registration Number? No. Your Company Registration Number (CRN) is issued by Companies House and appears on the public register. Your UTR is issued by HMRC for tax purposes only. They are different numbers used by different government bodies.
What if my company has been assigned multiple UTRs? This occasionally happens following a re-registration or an administrative error. Contact HMRC to identify the active UTR for your company.
Does a dormant company need a UTR? A dormant company registered for corporation tax will have a UTR and will normally be required to file a nil return each year. See our guide to dormant company corporation tax.
What happens if I use the wrong UTR when paying corporation tax? HMRC will be unable to allocate the payment to your account. Contact HMRC immediately to correct the payment reference. Meanwhile, HMRC may still issue late payment notices.
Summary
A UTR number is a 10-digit reference assigned by HMRC to every UK limited company that registers for corporation tax. It arrives by post within roughly 15 days of registration and is required for every company tax return, every tax payment, and every communication with HMRC about your company's tax affairs. Keep it safe and use it precisely as issued — it is the key reference for your company's entire tax history with HMRC.