A mechanism for consistent public land mobile network (PLMN) specific supplementary services across different PLMNs or different service areas/regions of a PLMN is provided. A visited PLMN in which a subscriber unit is receiving or is attempting to receive service may be identified. Home PLMN specific supplementary services provisioned for the subscriber unit may be mapped to visited PLMN specific supplementary service codes set forth in the visited PLMN. These visited PLMN specific supplementary service codes may be used to replace the home PLMN specific supplementary service codes and transmitted to the visited PLMN using outgoing Mobile Application Part messages.