Concur

The service provides online tools for business organizations to manage travel and expense reporting and reimbursement. Integrated travel booking functions combine with expense reporting within a single platform. The API allows integration with applications of customer companies, partner service providers, or independent third-party developers including mobile app developers. API methods support submission and tracking of travel requests and booking of transportation and lodging, either for individuals or for groups completing the same travel. Methods also support creating, updating, and submitting expense reports as part of a reimbursement process.

TripIt

The TripIt API allows users to access the TripIt's information about travel and itineraries. TripIt facilitates integration and organization of travel information from many different sources. The TripIt API allows third parties to easily interface with this platform.