Methods and apparatus of a wireless portable communication device for maintaining appropriate authentication credentials for accessing a data application maintained in a service network are provided. A default access point name (APN) or network access identifier (NAI) is maintained in memory of the wireless device. The wireless device submits, via a default wireless network, the default APN or NAI for establishing a data session in the default wireless network. The wireless device is then able to receive, in the data session via the default wireless network, a message service using the common data application maintained in the service network. In response to a change in service subscription for the wireless device, the wireless device receives, via a current cellular network, a current APN or NAI and stores it in its memory. The wireless device then submits, via the current wireless network, the current APN or NAI for establishing a data session in the current wireless network. The wireless device is then able to receive, in the data session via the current wireless network, the message service using the common data application maintained in the service network.