A master wireless device and a child wireless device execute respective device activation sequences. On the child wireless device, the activation sequence displays, on a display of the device, a non-textual image representing a unique child device credential. On the master wireless device, the activation sequence prompts a user to capture a digital picture of the child wireless device screen. The master wireless device presents its own credentials, along with information from the digital picture, to a service management system in a network, allowing the service management system to verify that the master wireless device is associated with a subscriber and is allowed to configure a child device, as well as verify the child device. Upon successful verification, the service management system activates the child wireless device to the subscriber account of the master wireless device.