How can i contact delta customer service? Customers can contact Delta Air Lines using the telephone number 800-455-2720 to reach Customer Care, which handles service comments and complaints. Those needing to make domestic flight reservations can call 800-221-1212, while customers needing international flight reservations can call 800-241-4141.How do i contact delta airlines by phone? Phone Number: You can contact Delta Airlines headquarters by phone at 1-404-715-2600. The corporate hours are from 8 a.m. to 5 p.m. Monday to Friday. Email: There is no corporate email listed on the Delta Airlines headquarters side of the website.