The present Inter-System Message Delivery System increases the SMS text message delivery success rate. When a mobile subscriber station roams outside of the confines of the cell in which it is presently registered, the delivery of SMS messages to mobile subscriber stations fails, since the mobile subscriber station is not present in the Serving Mobile Switching Center to receive the SMS message. This is particularly common when the mobile subscriber station is moving within the confines of a border cell or multiple cells of a Border Mobile Switching Center and is not yet registered at this Border Mobile Switching Center. The SMS message delivery process initiates a page to the mobile subscriber station via inter-system or inter-Mobile Switching Center paging. Once the mobile subscriber station is located, the bearer data for this mobile subscriber station is forwarded from the Serving Mobile Switching Center to the Border Mobile Switching Center in which the mobile subscriber station is presently located The mobile subscriber station is finally registered at the Border MSC.