The tax office reference number is your employer PAYE reference. Same thing, different name, depending on which HMRC document you are reading.
It looks like this: 123/AB456.
The reason this question gets asked so often is that HMRC issues four different reference numbers to a company that employs people, they all appear on overlapping documents, and using the wrong one has real consequences. Pay HMRC quoting the PAYE reference instead of the Accounts Office reference and the money goes somewhere you did not intend.
Here is each number, its format, where it lives, and which form wants which.
The four numbers, side by side
| Number | Format | Issued by | What it does |
|---|---|---|---|
| Employer PAYE reference | 123/AB456 | HMRC | Identifies your PAYE scheme |
| Accounts Office reference | 13 characters | HMRC | Tells HMRC's bank where to credit a payment |
| Corporation Tax UTR | 10 digits | HMRC | Identifies the company as a taxpayer |
| Company registration number | 8 characters | Companies House | Identifies the legal entity |
Two of those come from HMRC's PAYE side, one from HMRC's Corporation Tax side, and one is not a tax number at all.
The employer PAYE reference
The official format
HMRC's own design guidance is precise, and almost nobody quotes it:
3 digit tax office number, a forward slash, and a tax office employer reference, like 123/AB456
Broken down, that is:
- 3 numbers
- a forward slash
- between 1 and 10 characters, letters and numbers
The second part varies in length. That is why validation on third party forms so often rejects a perfectly valid reference: the form assumed a fixed length that HMRC never specified.
The first three digits identify the HMRC office that handles the scheme. Everything after the slash identifies the employer's PAYE scheme within it.
What it is called
HMRC notes it "may be called 'Employer PAYE reference' or 'PAYE reference'". You will also see it as tax office reference number, employer reference number, or ERN. All the same number.
Where to find it
| Document | Present |
|---|---|
| P60 | ✅ Issued after the end of the tax year |
| P45 | ✅ Issued when you leave a job |
| Payslips | ✅ Usually |
| Letters from HMRC about PAYE | ✅ |
| Real Time Information submissions | ✅ |
| The original PAYE registration letter | ✅ |
HMRC's guidance points at the two most reliable: it "will be on your P60" or "on letters from HMRC about PAYE".
If you are an employee who needs it, the P60 is the answer. If you are an employer who has lost it, the PAYE section of your HMRC online account holds it.
The Accounts Office reference, and why the confusion costs money
This is the number people get wrong, and the mistake is expensive rather than merely annoying.
The Accounts Office reference is a 13 character code, and it exists for one purpose: paying HMRC.
| Employer PAYE reference | Accounts Office reference | |
|---|---|---|
| Format | 123/AB456 | 13 characters |
| Purpose | Identifies who you are | Tells HMRC's bank where to credit money |
| Used on | P60, P45, payslips, RTI submissions | Payment remittances |
| Wrong one used | Form rejected, or misidentified scheme | Payment lands unallocated |
The clean way to remember it: the PAYE reference says who you are, the Accounts Office reference says where the money goes.
Quote the wrong one on a payment and HMRC receives money it cannot match to your scheme. You then have an apparent underpayment on a scheme that has, in fact, paid, and a reallocation to chase.
Which number goes on which form
This is the table nobody publishes, and it is the actual question behind the search.
| Situation | Number to use |
|---|---|
| Employee completing a tax return | Employer PAYE reference, from the P60 or P45 |
| Employee claiming a tax refund | Employer PAYE reference |
| Employer paying PAYE to HMRC | Accounts Office reference |
| Employer filing RTI | Employer PAYE reference |
| Employer registering for a pension scheme | Employer PAYE reference |
| Company filing a Corporation Tax return | Corporation Tax UTR |
| Company filing accounts at Companies House | Company registration number |
| Applying for a childcare or tax-free childcare scheme | Employer PAYE reference |
| CRS or FATCA self-certification | Neither, see the note below |
That last line matters for anyone dealing with a foreign bank or platform. The PAYE reference is not a tax identification number for international reporting purposes. That is a different question with a different answer, covered separately.
When you do not have one
Not every company has a PAYE reference, and that is normal.
A company with no employees does not need one. A single director who takes no salary, or who is paid entirely by dividend, may never register for PAYE.
A sole trader with no employees does not have one either. They have a UTR for Self Assessment, and nothing on the PAYE side.
Registration is what creates it. HMRC issues the reference when you register as an employer, and it arrives in the confirmation correspondence.
If a form insists on a PAYE reference and you genuinely have no PAYE scheme, the answer is that none has been issued, not a substitute number from elsewhere.
Common mistakes
Using the Accounts Office reference to pay, and the PAYE reference to identify, in reverse. The single most expensive error in the set.
Dropping the slash. 123AB456 is not the same string as 123/AB456 to a validation routine.
Assuming a fixed length after the slash. HMRC specifies between one and ten characters. A form that demands exactly six will reject valid references.
Confusing it with the UTR. Both come from HMRC, both appear on correspondence, and they identify completely different things. The UTR is ten digits with no slash.
Using the company registration number. It comes from Companies House, not HMRC, and has nothing to do with payroll.
Answers: who are you?
- On the P60 and the P45
- On payslips
- Quoted on PAYE correspondence
Answers: where does the money go?
- On the payment slips
- On the PAYE registration letter
- The reference every payment must quote
How this fits the rest
The PAYE reference is one of five British numbers that circulate, and the confusion between them is a recurring theme.
| Number | Answers |
|---|---|
| Employer PAYE reference | Which PAYE scheme is this |
| Accounts Office reference | Where does this payment go |
| UTR | Who is the taxpayer |
| VAT number | Is this business VAT registered |
| Company registration number | Does this legal entity exist |
Only three of those come from HMRC, only two are used for identification on tax forms, and exactly none of them is called a tax identification number, which is a separate problem in its own right.
The summary
| You want to | Answer |
|---|---|
| Find your tax office reference number | ✅ It is the employer PAYE reference, on your P60 or P45 |
| Know the format | ✅ 123/AB456: 3 digits, slash, 1 to 10 characters |
| Pay HMRC for PAYE | ❌ Use the Accounts Office reference, not this one |
| File RTI | ✅ Employer PAYE reference |
| Recover a lost reference as an employer | ✅ PAYE section of your HMRC online account |
| Use it as a tax identification number abroad | ❌ It is not one |
| Get one with no employees | ❌ No PAYE scheme, no reference, and that is normal |
Frequently asked questions
What is a tax office reference number?
It is the employer PAYE reference, the number HMRC uses to identify a PAYE scheme. It is formatted as three digits, a forward slash, then between one and ten letters and numbers, for example 123/AB456.
Where do I find my tax office reference number?
On your P60, issued after the end of the tax year, or your P45, issued when you leave a job. It also appears on payslips and on letters from HMRC about PAYE.
Is the tax office reference the same as the PAYE reference?
Yes. It is also called the employer PAYE reference, the employer reference number or ERN. They are all the same number.
What is the difference between the PAYE reference and the Accounts Office reference?
The PAYE reference identifies your scheme and appears on P60s, P45s and RTI submissions. The Accounts Office reference is a 13 character code used only when paying HMRC. Using the wrong one on a payment leaves the money unallocated.
What format is an employer PAYE reference?
Three digits, a forward slash, then between one and ten characters of letters and numbers, per HMRC's published guidance. The part after the slash varies in length, which is why some third party forms reject valid references.
Is the tax office reference number the same as my UTR?
No. The UTR is ten digits with no slash and identifies a taxpayer for Self Assessment or Corporation Tax. The PAYE reference identifies a payroll scheme.
What if my company does not have a PAYE reference?
Then it has no PAYE scheme, which is normal for a company with no employees or a director paid only in dividends. HMRC issues the reference when you register as an employer.
Can I use the tax office reference as a tax identification number?
No. It identifies a payroll scheme, not a taxpayer, and it is not the answer to a request for a UK tax identification number on a CRS or FATCA form.
How do I recover a lost employer PAYE reference?
Check the PAYE section of your HMRC online account, or any letter HMRC has sent you about PAYE. Your payroll provider will also hold it.
Sources
The employer PAYE reference format is quoted from HMRC's published design pattern guidance, consulted in August 2026. The distinction between the employer PAYE reference and the Accounts Office reference reflects HMRC's own usage. Where a number appears on a given document is described from the standard layout of HMRC forms and may vary by payroll provider. This is informational, not tax advice.