Various aspects of the present disclosure include methods, network servers or components and user equipment devices configured to authorize network slices that are associated with services provided by external providers. Various aspects enable access and use of network slices by user equipment devices connected to a network (e.g., 5G or New Radio network) via network components associated with a service provider by generating an allowed network slice selection assistance information (Allowed NSSAI) and an Unauthorized NSSAI, and sending the Allowed NSSAI and Unauthorized NSSAI to a user equipment device.