A subscriber information authentication system that compares network-obtained and device-obtained information to verify that a device being used in connection with a user account is authenticated for that account. Certain subscriber information may be associated with the account during a registration process. In subsequent attempts to access the account, the registered subscriber information may be used in conjunction with information obtained from a telecommunication network and from a device to verify that the device is authorized. The information from the telecommunication network may be queried using Signaling System No. 7 (“SS7”) protocols. The device authorization may be performed, for example, to ensure that a device being used for device-based verification is the device a user purports it to be.