Systems and techniques are disclosed to facilitate the sponsored connectivity of a user equipment on a serving network so that the UE may access a service whose connectivity is sponsored by an application service provider. The application service provider provisions the serving network so that it is aware of the sponsored connectivity. In an attach attempt to the serving network, the UE provides a client token based on a pre-existing credential (established between the UE and the application service provider) instead of a subscriber identifier with the attach request. The application service provider's server validates the access credential to authenticate the UE and provides information that the serving network uses to mutually authenticate with the UE. The UE may then use the serving network to access the service via the sponsored connection, even where the UE does not have a subscriber identity and subscription with a cellular network.