Employer Reference Number (ERN)

What It Is and How to Find It

An Employer Reference Number (ERN) is a unique set of letters and numbers used by HM Revenue and Customs (HMRC) to identify an employer's PAYE (Pay As You Earn) scheme.

If you need to submit your ERN to us, you can use our form here.

The ERN is crucial for tax purposes and is often required when conducting employment-related processes – such as buying Employers’ Liability insurance. It serves as a key identifier ensuring that tax and National Insurance contributions are correctly recorded against the right employer's account.

Employers receive an ERN when they register with HMRC as an employer, a process that is integral to the operation of PAYE.

The number is provided by HMRC and typically consists of a three-digit HMRC office number, followed by a reference number unique to the employer. It can usually be found on the documentation and correspondence from HMRC regarding PAYE, such as on a P45, P60, P11/D, or on the welcome letter from HMRC when the PAYE scheme is set up.

For employees, locating an ERN is straightforward if they have access to those documents. However, if these are not readily available, the number can also be requested from an employer's payroll department or by directly contacting HR. It is the responsibility of the employer to keep their ERN confidential and secure, as it is a critical piece of information for accurate tax records and compliance with HMRC regulations.

Where to Find Your ERN

If you need to find your ERN, you can find it on your original documents from HMRC after you registered as an employer. If these have been misplaced, then you should also be able to see it on any of the below documents you have previously issued to employees:

  • Payslips – the ERN is often included on each payslip issued
  • P60 form – this is issued at the end of each tax year
  • P45 form – these are provided when an employee leaves a company

The format of the ERN is usually two parts: a three-digit HMRC office number, followed by a unique reference number for the employer.

Why You Need to Provide Your ERN When Buying Employers’ Liability Insurance

All employers are obliged to hold valid Employers' Liability insurance with a minimum cover of £5 million from an authorised insurer. This insurance protects businesses and employees in case of work-related injuries or illnesses. The ERN must be provided to the insurance provider and will be registered with the Employers' Liability Tracing Office (ELTO), facilitating the tracing of historical insurance policies.

The HMRC ERN helps you identify which firms an employee has worked for in the past, in case they make a claim against you for an illness or injury that could have happened under a different employer.

Submit your ERN to us

If you have recently purchased an Employers' Liability Insurance policy from us but didn't have your Employer Reference Number (ERN) available at the time, you can use the form below to submit your ERN to us now.