1. A network system for providing network access service notification messages containing information about a network access activity of an end-user device, the network system comprising: a first service design center configured to: obtain a first network access notification message policy comprising a first network access trigger condition and an associated first network access notification message, the first network access trigger condition comprising one or more current or requested end-user device network access activities, the first network access notification message comprising notification information to be presented to a user through a user interface, receive a trigger condition indication from a network element, associate the trigger condition indication with the first network access notification message, and present the notification information to the user through the user interface; a network provisioning instruction translator configured to: receive, from the first service design center, the first network access trigger condition, and determine, based on the first network access trigger condition, one or more network access trigger identification instructions; and a network provisioning system configured to communicate the one or more network access trigger identification instructions to one or more network elements responsible for monitoring the service usage, the one or more network elements responsible for monitoring the service usage configured to: execute the one or more network access trigger identification instructions to identify when the first network access trigger condition occurs, and send the trigger condition indication to the first service design center.