Every PAYE scheme has two numbers. The employer PAYE reference (a three digit HMRC office number, a slash, then letters and numbers) identifies the scheme for reporting, and is the number employees, insurers and the Pensions Regulator ask for. The 13 character Accounts Office reference identifies the scheme’s payment account, and is the number you quote when you pay HMRC.

What are the two references?

HMRC’s field guide, Payroll information to report to HMRC, describes both.

Employer PAYE reference Accounts Office reference
Shape A 3 digit HMRC office number, then a slash, then letters and numbers 13 characters in the format 123PA00012345
Main job Identifies the PAYE scheme in returns and on employee documents Identifies the scheme’s account when money is paid in
Typical users Payroll software, employees, pension and insurance providers Your bank, HMRC’s payment systems, PAYE Online

HMRC’s own Self Assessment notes for the employment pages (SA102) use 139/H345 as an example of an employer PAYE reference. On an FPS or EPS the reference is split into two fields: the HMRC office number (the three digits before the slash) and the employer PAYE reference (the letters and numbers after it).

Where do you find them?

Both arrive in the letter HMRC sends after you register as an employer. GOV.UK says you must register before the first payday to get the employer PAYE reference, and cannot register more than two months before you start paying people. If an accountant or adviser registered for you, the letter goes to them, which is a common reason a business owner cannot find the Accounts Office reference.

After that:

  • the Accounts Office reference is shown in the HMRC online account once you are enrolled for PAYE Online, and HMRC’s field guide says it is available online if you pay electronically;
  • the HMRC office number also appears on P6 and P9 tax code notices;
  • the employer PAYE reference is printed on every employee’s P45 and P60, which is why the SA102 form tells employees to copy it from there.

Where is the employer PAYE reference used?

  • Every RTI return. The office number and reference go on every Full Payment Submission and Employer Payment Summary, so HMRC can match the pay you report to the right scheme. See Real Time Information: FPS and EPS.
  • Apprenticeship Levy. Employers reporting the levy put the office number and PAYE reference to which the levy return relates on the EPS.
  • Employees’ documents and tax returns. It appears on the P45 and P60, and an employee filing Self Assessment enters it in box 4 of each SA102 employment page.
  • Automatic enrolment. The Pensions Regulator says you need your PAYE reference, plus either your letter code or your Accounts Office reference, to start your declaration of compliance. Its duties are covered in automatic enrolment employer duties.
  • Employers’ liability insurance. FCA rules in ICOBS 8 Annex 1 require insurers to include an employer reference number (ERN) on their employers’ liability register, and the FSA’s 2011 policy statement PS11/04 describes ERNs as the numbers provided by HMRC. That is why insurers ask for it, and how former employees trace old policies through the Employers’ Liability Tracing Office.

Where is the Accounts Office reference used?

  • Payments. HMRC’s Pay employers’ PAYE guidance says you use the 13 character Accounts Office reference, with no spaces, as the payment reference for Direct Debit, bank transfer, online payment and cheque. For an early or late payment you add four extra digits for the tax year and tax month; the method is explained in how to pay HMRC.
  • Every RTI return. It is also a required field on the FPS and EPS, alongside the employer PAYE reference.
  • PAYE Online enrolment. If you did not register online, enrolling for PAYE Online needs both the PAYE reference and the Accounts Office reference from the registration letter.
  • Changing payment frequency. To register as an annual scheme, HMRC’s Running payroll guidance says to call the employer helpline with your 13 character Accounts Office reference.

A simple way to remember it: if money is moving, quote the Accounts Office reference; if information about people and pay is moving, quote the employer PAYE reference. RTI returns carry both.

What if you need to pay staff before the reference arrives?

GOV.UK’s registration guidance says that if you pay an employee before you have the employer PAYE reference, you should run payroll, store the FPS, and send it late once the reference arrives. HMRC’s Running payroll guidance lists “You’ve not received your employer PAYE reference yet” as an accepted reason for a late FPS: send it as soon as possible after the reference arrives and select late reporting reason code G. Do not invent a reference to get the software to file.

Act promptly once the letter comes. Running payroll warns that HMRC will close the PAYE scheme of a new employer that does not send a report to, or pay, HMRC within 120 days.

How does it look in practice?

Illustration only. A new company, Riverside Cafe Ltd, receives its registration letter showing an employer PAYE reference of 123/AB45678 and an Accounts Office reference of 123PA00098765. In its payroll software it enters 123 as the HMRC office number, AB45678 as the employer PAYE reference and 123PA00098765 as the Accounts Office reference. Its October payroll is paid on 28 October 2026, and it pays HMRC by bank transfer on 20 November 2026 using 123PA00098765 on its own, because the payment is on time. Its pension provider asks for “the PAYE reference” for the declaration of compliance, and the company gives 123/AB45678. Its insurer asks for the ERN on the employers’ liability proposal, and gets the same number.

What goes wrong when the references are mixed up?

A payment quoting the wrong reference may be delayed or credited to a different tax bill, according to HMRC’s payment guidance, and you then need the employer helpline to move it. Meanwhile the scheme that should have been paid shows as unpaid, which can lead to interest and late payment penalties.

Other common problems:

  • Giving an employee the Accounts Office reference for their tax return instead of the employer PAYE reference shown on the P60.
  • Typing the whole employer PAYE reference, slash included, into the reference field of an RTI return when the software expects the office number separately.
  • Using an old scheme’s references after a business restructure or change of payroll provider, so returns and payments do not match.
  • Assuming a payroll bureau holds the registration letter, when the client needs the references for insurance, pensions and banking too. Payroll bureau compliance covers what a bureau should hold.

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Reviewed by Christine Anderson, Broker, Solar Protect. Last reviewed 19 October 2026. Part of Accountapedia, the Solar Protect guide to UK tax and accounting. This page is general information, not personalised advice.