A device-type locking procedure is disclosed, where a trusted execution environment (TEE) of a user device retrieves a telecommunication service plan type identifier stored on an identification module of the user device. The TEE of the user device then initiates a service authentication procedure for a telecommunication service provider of the user device, based on the received plan type identifier and in conjunction with an optional service plan provisioning process. A service plan indicated by the plan type identifier is subsequently compared to a designated user device service plan via the TEE. Based on the comparison results, a determination is then made as to whether the user device should be locked or unlocked, depending on the device's current operating state.