You've spotted "tax reference" on a payslip, a P60, or a letter from HMRC, and you're not sure what it's actually pointing at. You're not alone. It's one of the most common things people ask us about, partly because HMRC uses several different reference numbers and they're easy to mix up.
In plain terms, a "tax reference" almost always means your employer's PAYE reference number, the unique code HMRC uses to identify the business that pays you.
This guide explains what it means, where to find it, what it looks like, how it differs from a UTR, and what to do if yours looks wrong. We'll keep it practical and use the 2025/26 tax year for any figures.
What is a tax reference?
A tax reference, more precisely called an Employer PAYE Reference, is the unique identifier HMRC assigns to every employer and pension provider that runs payroll in the UK.
It identifies a specific employer's tax records with HMRC. Every time your employer reports pay or pays over tax and National Insurance, that activity is logged against this reference.
You'll see the same thing called by several names. They all mean the employer's PAYE reference:
- Tax reference number
- Employer reference number
- Employer PAYE reference
- PAYE reference
It is not your personal tax identifier. The number that's unique to you as an individual is your National Insurance number.
What is a tax reference number used for?
The reference does a few jobs inside the PAYE (Pay As You Earn) system.
It identifies which employer is submitting payroll, paying tax, or asking a question, so everything is credited to the right account.
When your employer reports your pay to HMRC under Real Time Information (RTI), the tax reference links that report to the correct employer. That reporting feeds into how your tax code is set and applied.
It also helps when you contact HMRC. If you ring up about your employment income, tax code, or a deduction, HMRC may ask for your employer's PAYE reference to find the right records quickly.
Where can you find your tax reference number?
You'll usually find your employer's PAYE reference on the payroll documents you already have.
On your payslip. The most accessible place. Look for a field labelled "tax reference", "employer reference", or "PAYE reference", often near your National Insurance number and tax code.
On your P60. This is the end-of-year certificate showing your total pay and deductions for the tax year (6 April to 5 April). Employers must give every employee a P60 by 31 May after the tax year ends. The reference appears on it.
On your P45. If you leave a job, your P45 shows your pay and tax to your leaving date, along with the employer's PAYE reference.
From your payroll or HR team. If you can't find it on a document, just ask. Payroll use the reference for every submission, so they can give it to you straight away. Have your name, payroll number, and National Insurance number handy.
If you've left a job and your former employer is no longer reachable, you can ask HMRC. The relevant contact details are on the gov.uk PAYE income tax contact page, and you'll need your National Insurance number and the employer's details.
What does a tax reference number look like?
An employer PAYE reference has a recognisable two-part format: three digits, a forward slash, then a mix of letters and numbers.
A typical example looks like 123/AB45678.
- The first three digits are the HMRC office number that set up the employer's scheme.
- The part after the slash is the unique employer identifier.
The number of characters after the slash varies, so the reference doesn't have a fixed length. The important thing is to quote it in full, including the slash. Writing 123AB45678 without the slash may not be recognised.
Here's how the main HMRC reference numbers compare.
| Reference type | Format | Who has it | What it's for |
|---|---|---|---|
| Employer PAYE reference | 3 digits / letters and numbers | Employers, pension providers | Identifying the employer in PAYE |
| Unique Taxpayer Reference (UTR) | 10 digits | Self-employed, partnerships, companies | Self Assessment, Corporation Tax |
| National Insurance number | 2 letters, 6 digits, 1 letter | Individuals | Your personal tax record |
| VAT registration number | 9 digits (sometimes with GB prefix) | VAT-registered businesses | VAT returns |
When a form asks for a "tax reference number type", it usually wants to know whether you're giving a PAYE reference, a UTR, a Corporation Tax reference, or a VAT number. Make sure you give the right one for the query.
What is the difference between a PAYE reference and a UTR?
These two get confused constantly, but they're entirely separate identifiers.
| Feature | Employer PAYE reference | Unique Taxpayer Reference (UTR) |
|---|---|---|
| Format | 3 digits / letters and numbers | 10 digits |
| Who has it | Employers and pension providers | Self-employed people, partnerships, companies |
| Purpose | Identifies the employer in PAYE | Identifies a taxpayer for Self Assessment or Corporation Tax |
| Where to find it | Payslip, P60, P45 | Self Assessment paperwork, Corporation Tax notices |
| Issued when | An employer registers for PAYE | You register for Self Assessment, or a company is formed |
Plenty of people have both. If you're employed and also run a side business or a company, HMRC will quote whichever reference fits the matter in hand.
Illustrative example. Sarah is employed and also freelances. HMRC writes to her about her employment under her employer's PAYE reference, and about her freelance income under her own UTR. Same person, two different references, two different purposes.
The rule of thumb: a PAYE reference has a slash in it, a UTR is ten plain digits.
What if you have more than one employer?
Each employer you work for runs its own PAYE scheme with its own reference. So with two jobs you'll have two different references, two sets of payslips, and two P60s at year end.
With more than one job, HMRC normally gives your tax-free Personal Allowance (£12,570 for 2025/26) to your main job and taxes the others in full. Common secondary tax codes are:
- BR taxes all income at the basic rate, 20% for 2025/26.
- D0 taxes all income at the higher rate, 40% for 2025/26.
- D1 taxes all income at the additional rate, 45% for 2025/26.
Each coding notice HMRC sends shows the employer's PAYE reference, so you can tell which job it relates to.
Illustrative example: two jobs in 2025/26
David has two jobs in the 2025/26 tax year.
Job 1, his main job: salary £35,000, tax code 1257L (Personal Allowance allocated here), employer reference 456/AB12345.
Job 2: salary £15,000, tax code BR, employer reference 789/CD67890.
His Income Tax for the year works out like this:
- Job 1: £35,000 less the £12,570 Personal Allowance leaves £22,430 taxable at 20%, which is £4,486.
- Job 2: BR means no allowance here, so the full £15,000 is taxed at 20%, which is £3,000.
- Total Income Tax: £7,486.
The two different references let David match each coding notice to the right job. (This example covers Income Tax only and ignores National Insurance, which is worked out separately on each job.)
If you want to sanity-check your own split across jobs, our income tax calculator and take-home pay calculator will do the sums for you.
What should you do if your tax reference is wrong?
If the reference on your payslip looks wrong, it's worth sorting out, because an incorrect reference can mean your pay and tax aren't being recorded against the right employer.
Start with payroll. This is nearly always an employer-side error in the payroll software. Ask your payroll or HR team to check their PAYE registration details and correct it.
Check whether the business changed. A reference can legitimately change if the employer restructures, is sold, or changes legal entity (for example, from a sole trader to a limited company). In those cases your employer and HMRC update the records, and you don't need to do anything.
Escalate to HMRC if needed. If your employer can't or won't fix it, contact HMRC using the details on the gov.uk income tax contact page. Have your National Insurance number, your employer's name, and the reference in question ready.
A quick word for employers: getting the right PAYE reference onto every payslip, P60, and RTI submission is part of running a compliant scheme. If that side of things feels like a chore, our bookkeeping and payroll support keeps it tidy.
What other HMRC reference numbers exist?
HMRC issues different references for different taxes. The ones you're most likely to meet are:
- Unique Taxpayer Reference (UTR): a 10-digit number for Self Assessment, also used by partnerships and companies.
- VAT registration number: 9 digits (sometimes shown with a GB prefix) for VAT-registered businesses.
- National Insurance number: your personal identifier, format two letters, six digits, one letter.
- Accounts Office reference: used by employers when paying PAYE over to HMRC, separate from the PAYE reference itself.
If you run a business, you can easily end up holding several of these at once: a PAYE reference if you employ people, a UTR for Self Assessment, a company UTR, and a VAT number. Keep a clearly labelled, secure record of each so you always quote the right one.
Frequently asked questions
What does tax reference mean?
A tax reference, properly called an Employer PAYE Reference, is the unique identifier HMRC assigns to every employer and pension provider in the UK. It's made up of three digits, a slash, then letters and numbers, for example 123/AB45678. It identifies the employer in the PAYE system and is used to track Income Tax and National Insurance for that employer's staff.
Where do I find my tax reference number on my payslip?
Your employer's PAYE reference appears on your payslip, usually in a field labelled "tax reference", "employer reference", or "PAYE reference", often near your National Insurance number and tax code. It also appears on your P60 and P45.
What is a UK tax reference number example?
A UK employer PAYE reference follows the format 123/AB45678. The first three digits are the HMRC office number that set up the scheme, and the characters after the slash uniquely identify the employer. The number of characters after the slash varies, but the three-digit-then-slash format stays the same.
What is the difference between a PAYE reference and a UTR?
A PAYE reference identifies an employer and contains a slash (123/AB45678). A UTR is a 10-digit number issued to individuals for Self Assessment or to companies for Corporation Tax (1234567890). You can have both if you're employed and also self-employed or run a company, but they serve different purposes.
How many digits is a tax reference number?
An employer PAYE reference has no fixed length because it mixes numbers and letters: three digits, a forward slash, then a variable run of letters and numbers. Always quote it in full, including the slash.
Does your tax reference number change?
It usually stays the same throughout your employment. It can change if your employer restructures, is sold, or changes legal entity, for example from a sole trader to a limited company. Your employer and HMRC handle the change, and your future payslips show the new reference.
What if I have more than one employer in 2025/26?
Each employer runs its own PAYE scheme with its own reference, so you'll see a different reference on each payslip. HMRC normally gives your Personal Allowance (£12,570 for 2025/26) to your main job and taxes the others with a code like BR, D0, or D1. Each coding notice shows the relevant employer's reference.
