The present document describes the stage 3 protocol and data model for the N5g-eir Service Based Interface between the 5G-EIR and its consumers over which the service to check the equipment identity as described in 3GPP TS 23.501 [2] is performed. It provides the stage 3 protocol definitions and message flows@ and specifies the API for each service offered by the 5G-EIR. The 5G System stage 2 architecture and procedures are specified in 3GPP TS 23.501 [2] and 3GPP TS 23.502 [3]. The Technical Realization of the Service Based Architecture and the Principles and Guidelines for Services Definition are specified in 3GPP TS 29.500 [4] and 3GPP TS 29.501 [5].