Southwest expects to be live in Sabre for corporate travel bookings by Labor Day.
The start-up date, if achieved, would come nine months after the companies came to a full-participation agreement in early January.
The content will be available for travel management companies, corporations and government agencies, but not for leisure travel agencies.
Last year Southwest went live for corporate bookings in Amadeus and in Travelport's Apollo, Worldspan and Galileo GDSs.