A business tax reference number is an identification number used by HM Revenue and Customs (HMRC) to connect a person or business with a particular tax record.
In most cases, someone asking for a business tax reference number means the 10-digit Unique Taxpayer Reference (UTR).
However, businesses can have several reference numbers, including a Corporation Tax UTR, Self Assessment UTR, VAT registration number and PAYE employer reference. The correct place to find the number therefore depends on the business structure and the tax concerned.
What Is a Business Tax Reference Number?
A business tax reference number allows HMRC to identify the correct tax account when processing returns, payments and correspondence.
The number required will depend on whether the business is a sole trader, partnership, limited company, VAT-registered organisation or employer.
A UTR normally contains 10 digits. It may appear with spaces on an HMRC letter, but it should be entered as one continuous number when a form or online service requests it.
A business may have more than one tax reference. For example, a limited company that employs staff and charges VAT could have:
- A Corporation Tax UTR
- A VAT registration number
- A PAYE employer reference
- An Accounts Office reference
- A Companies House registration number
These numbers are not interchangeable. Entering a company registration number where a Corporation Tax UTR is requested could delay a return, payment or registration.
Which Business Reference Number Do You Need?
The following table explains the most common UK business reference numbers.
| Reference number | Typical format | Who uses it? | Main purpose |
| Unique Taxpayer Reference | 10 digits | Sole traders and Self Assessment taxpayers | Identifies the person’s Self Assessment record |
| Corporation Tax UTR | 10 digits | Limited companies | Identifies the company’s Corporation Tax record |
| Partnership UTR | 10 digits | Business partnerships | Used for the partnership tax return |
| VAT registration number | 9 digits | VAT-registered businesses | Used on VAT returns and VAT invoices |
| PAYE employer reference | Usually three digits followed by letters and numbers | Employers | Identifies the employer’s PAYE scheme |
| Accounts Office reference | 13 characters | Employers | Used when paying PAYE and National Insurance |
| Company registration number | Usually eight characters | Limited companies | Identifies the company at Companies House |
The company registration number is not a tax reference. It is issued by Companies House when the company is incorporated, whereas HMRC issues tax references.
How Can a Sole Trader Find Their UTR Number?
A sole trader normally uses a personal Self Assessment UTR. It is issued after the person registers with HMRC for Self Assessment.
The UTR may be available in the individual’s:
- Personal tax account
- HMRC mobile app
- Previous Self Assessment tax return
- Self Assessment registration letter
- Tax calculation or statement
- HMRC payment reminder
- Correspondence from an accountant
The number may be labelled UTR, Unique Taxpayer Reference, tax reference or Self Assessment UTR.
A person who has recently started trading may not have a UTR unless they have completed the relevant registration. Understanding when to register with HMRC can help a new owner avoid missing important tax deadlines.
A sole trader should not use their National Insurance number as a substitute for a UTR. The two numbers have different purposes, even though HMRC may ask for both when verifying an identity.
How Can a Limited Company Find Its Corporation Tax UTR?
A limited company receives its own 10-digit Corporation Tax UTR. It belongs to the company as a separate legal entity and is different from any personal UTR held by its directors.
The number can normally be found in:
- The company’s HMRC business tax account
- Corporation Tax registration correspondence
- Notices to deliver a Company Tax Return
- Previous Company Tax Returns
- Corporation Tax payment reminders
- Letters sent to the registered office
- Records held by the company’s accountant
After someone registers a new company, Companies House passes the incorporation information to HMRC. HMRC will normally send Corporation Tax information to the company’s registered office.
The envelope and letter should be stored securely because they contain information needed to manage the company’s tax account.
Can a Corporation Tax UTR Be Found at Companies House?
A Corporation Tax UTR cannot normally be found on the public Companies House register. Companies House displays details such as the company name, registration number, registered office, filing history and officers, but it does not publicly display the company’s UTR.
This is an important security measure. A UTR should not be added to a public website, marketing material or ordinary customer invoice.
The company registration number shown at Companies House may look similar to a tax reference, particularly when it contains eight digits. However, it cannot be used in place of the 10-digit Corporation Tax UTR.
How Can a Partnership Find Its Tax Reference?
A partnership receives a UTR for the partnership itself. Each individual partner may also have a separate personal UTR for their own Self Assessment return.
The partnership UTR can usually be found on:
- The partnership registration letter
- A previous partnership tax return
- HMRC reminders and statements
- The nominated partner’s tax records
- Correspondence held by the partnership’s accountant
Care is needed when completing returns. The partnership UTR belongs on the partnership return, while each partner’s personal UTR belongs on their individual Self Assessment return.
Where Can a VAT Registration Number Be Found?
The VAT registration number is not the same as a UTR. It contains nine digits and is issued only after HMRC approves the VAT registration.
A business can usually find its VAT number on:
- Its VAT registration certificate
- Its online VAT account
- Previously submitted VAT returns
- VAT notices from HMRC
- VAT invoices produced by the business
- Records held by its accountant or bookkeeper
Businesses preparing to become VAT registered should not charge VAT until the registration rules allow them to do so. Once registered, the VAT number should appear on valid VAT invoices.
Businesses also need to maintain suitable digital records and understand the relevant Making Tax Digital rules when managing VAT submissions.
Where Can an Employer Find Its PAYE Reference?
A business receives a PAYE employer reference when it registers as an employer. The reference is often divided into two sections and may look similar to 123/AB456.
It can usually be found on:
- The employer registration confirmation
- HMRC PAYE correspondence
- Payroll software
- Previous payroll reports
- P60 and P45 forms
- Records held by the payroll provider or accountant
Employers may also have a 13-character Accounts Office reference. This is used when making PAYE and National Insurance payments. It should not be confused with the shorter PAYE employer reference used for payroll reporting.
How Can a Lost Business Tax Reference Be Recovered?
The first step is to identify which reference number is missing. The business should then check its online tax account, previous returns, registration letters, tax calculations and accounting records.
If the number still cannot be located, the business owner can request it from HMRC. For security reasons, HMRC may ask questions about the taxpayer, business, registered address and recent tax records before releasing or reissuing information.
A limited company should make sure its registered office is current because HMRC may send the Corporation Tax UTR by post rather than provide it immediately through an unsecured communication channel.
The following information may be needed during the recovery process:
- Full name or registered company name
- Business address or registered office
- Company registration number
- National Insurance number for an individual
- Date the business began trading
- Nature of the business
- Relevant tax registration details
Only an authorised director, partner, taxpayer or appointed agent may be able to access certain records.
What If HMRC Has Not Issued a UTR Yet?
A missing UTR does not always mean it has been lost. HMRC may not have issued one because the business has not completed the appropriate tax registration.
A new sole trader generally needs to register for Self Assessment. A limited company must inform HMRC when it becomes active for Corporation Tax, even though it has already been incorporated at Companies House.
Understanding when business tax starts can help owners determine which registrations and reference numbers should already be in place.
Processing can take time, particularly if the application contains incomplete details or HMRC needs to carry out additional checks. The business should avoid submitting repeated applications unless instructed to do so, as duplicate registrations could create conflicting records.
How Should Business Tax References Be Stored?
Tax reference numbers should be kept in a secure, organised location. They will be needed for returns, payments, payroll reporting, accountant authorisation and communication with HMRC.
A simple reference record could include:
| Tax record | Number to store | Where it is kept |
| Self Assessment | Personal UTR | Secure personal tax folder |
| Corporation Tax | Company UTR | Company tax records |
| VAT | VAT registration number | VAT records and invoices |
| PAYE | Employer reference | Payroll system |
| PAYE payments | Accounts Office reference | Payroll payment records |
| Companies House | Company number | Statutory company records |
Reliable small-business accounting software may help organise financial records, but access to sensitive tax details should still be restricted to authorised people.
Businesses should not publish a UTR or send it through an unsecured message. Although VAT numbers and company registration numbers commonly appear on business documents, UTRs should generally remain private.
What Common Mistakes Should Be Avoided?
The most common mistake is assuming that every business has one universal tax number. In reality, different tax accounts carry different references.
Other frequent errors include using a director’s personal UTR for a limited company, confusing a partnership UTR with a partner’s UTR, entering the Companies House number on a Corporation Tax form, or using the PAYE employer reference when making a PAYE payment that requires the Accounts Office reference.
Checking the wording on the form is usually the quickest way to determine which number is required.
Conclusion
The quickest way to find a business tax reference number is to check the relevant HMRC online account, registration letter, previous tax return or payment notice.
Sole traders use a personal Self Assessment UTR, while limited companies have a separate Corporation Tax UTR. Partnerships, VAT-registered businesses and employers may hold additional references.
Because each number serves a different purpose, business owners should confirm exactly which reference has been requested before submitting a form or making a payment.
Frequently Asked Questions
Is a business tax reference the same as a UTR?
The phrase often refers to a UTR, but it could also mean a VAT number, PAYE employer reference or another tax-specific identifier.
How many digits are in a business UTR?
A UK Unique Taxpayer Reference normally contains 10 digits.
Does every limited company have a UTR?
A limited company registered for Corporation Tax will have its own UTR. It is separate from the UTR of any director.
Can a UTR be found on a payslip?
A personal or company UTR is not normally shown on a payslip. A payslip may display an employer’s PAYE reference instead.
Can an accountant find a company’s UTR?
An authorised accountant may be able to find it in the company’s records or access relevant information through authorised tax services.
Is a company number the same as a tax reference?
No. Companies House issues the company registration number, while HMRC issues the Corporation Tax UTR and other tax references.
Should a UTR appear on business invoices?
A UTR is not normally required on customer invoices and should be kept private. A VAT-registered business must include its VAT number on valid VAT invoices.
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