UK tax identification numbers: UTR, NI, VAT and company numbers

The UK does not have one tax identification number. Instead you may hold several: a UTR for Self Assessment or Corporation Tax, a National Insurance number, a VAT number, a company number from Companies House and, if you employ staff or trade abroad, PAYE and EORI references. This page shows what each looks like, where to find it and when you need it.

What are the main UK tax reference numbers?

There are six references most people and businesses meet. The table shows the format of each, using HMRC’s own examples.

UTR (Unique Taxpayer Reference)

A UTR is a 10-digit number HMRC issues when you register for Self Assessment or set up a limited company. GOV.UK says it may be called simply a “tax reference”. HMRC posts it about 15 days after you register.

Individuals, sole traders, landlords, partnerships, trusts and companies each have their own UTR. A company’s Corporation Tax UTR is not the same as its company number. See how to find your UTR number for the five places to look.

National Insurance number

A National Insurance number is your personal reference for National Insurance and tax. GOV.UK says it is made up of 2 letters, 6 numbers and a final letter, and it never changes.

HMRC usually sends a letter with your number shortly before your 16th birthday. It is also on payslips and your P60. Employers need it to run payroll. See National Insurance rates for 2026/27 for what you pay.

VAT registration number

A UK VAT number is 9 digits, and businesses often show it with GB in front. HMRC’s design guidance says it appears on the VAT registration certificate.

VAT-registered businesses must show it on VAT invoices. You can check a supplier’s number with HMRC’s Check a UK VAT number service, which shows the name and address it is registered to. Our VAT registration guide covers when you must register.

Company registration number

Companies House gives every company and LLP a registration number when it is incorporated. It is shown on the certificate of incorporation and on the company’s page on Companies House’s Find and update company information service.

Company numbers have 8 characters. English and Welsh companies usually have 8 digits, padded with leading zeros, such as 08725503. Companies House WebFiling also accepts numbers with these prefixes:

• SC and NI: limited companies registered in Scotland and Northern Ireland (WebFiling also lists RO)
• OC, SO and NC: limited liability partnerships

Company directors now also have a Companies House personal code after verifying their identity. That is a separate reference; see your Companies House personal code.

Employer PAYE and accounts office references

Employers have two PAYE references, and mixing them up is a common payroll error.

• Employer PAYE reference: a 3-digit tax office number, a forward slash and a reference of up to 10 letters or numbers, such as 123/AB456. It is on P60s and HMRC letters about PAYE.
• Accounts office reference: a 13-character reference used when paying HMRC. GOV.UK says it is in your HMRC online account and on the letter HMRC sent when you registered as an employer.

Read more in setting up PAYE.

EORI number

An EORI number lets a business move goods into or out of Great Britain. HMRC’s EORI design guidance says GB and XI numbers are 14 characters: the 2-letter code plus 12 digits. XI numbers are for goods moving to or from Northern Ireland.

Which number should I give as my UK TIN?

Give the reference HMRC treats as your Tax Identification Number (TIN) for international reporting. HMRC’s International Exchange of Information Manual, at IEIM8000445, sets this out.

• If you are an individual: your National Insurance number will usually be your TIN.
• If you are a company: your company registration number will normally be the TIN.
• If you are an LLP: use the company registration number.
• If you are a partnership: use the partnership UTR.
• If you are a trust: use the trust UTR.

Foreign banks, brokers and crypto platforms ask for a TIN under the Common Reporting Standard and similar rules. Some forms ask for your UTR instead, so read the label carefully.

What to do now

1. List every reference your business holds in one secure place.
2. Check the VAT numbers on supplier invoices before you reclaim VAT.
3. Give your payroll provider both PAYE references, labelled clearly.
4. Keep HMRC’s telephone numbers handy in case one goes missing.

Frequently asked questions

Does the UK have a tax identification number?

Not a single one. HMRC treats the National Insurance number as the usual TIN for individuals and the company registration number as the TIN for companies.

Is a UTR the same as a National Insurance number?

No. A UTR is a 10-digit tax reference for Self Assessment or Corporation Tax. A National Insurance number has letters and numbers, such as QQ123456B.

How many digits is a UK VAT number?

A UK VAT registration number is 9 digits. It is often written with GB in front, such as GB123456789.

Is my company number the same as my company UTR?

No. Companies House issues the company number, which is usually 8 characters. HMRC issues the 10-digit Corporation Tax UTR separately.

What is the difference between a PAYE reference and an accounts office reference?

The employer PAYE reference, such as 123/AB456, identifies your payroll scheme. The 13-character accounts office reference is what you quote when you pay HMRC.