Consistent data across applications is the centerpiece for a successful integration of IT systems. Heterogeneous IT environments, as found in most mature industries, pose a challenge not only in integrating applications, but also in ensuring a consistent set of data being used. Based on an industry example we describe how data consistency is realized through data modeling concepts and a service-oriented architecture. A directory service and adapters handle the information transfer between applications using a global information model derived from an industry standard. Two use cases show how a synchronization service reacts and resolves data inconsistencies.