Insurers providing Employers Liability Insurance are required to register the policy with the Employers Liability Tracing Office (ELTO). In order to do this they will ask for customers' Employer Reference Number (ERN).
The ERN is also known as the Employer PAYE Reference and is given to every business that registers with HMRC. This number can be found on forms P45, P60, P11D as well as any correspondence from HMRC relating to PAYE.
