Delta Airlines cancellation policy » depend on several things, including the type of ticket you purchased, when you cancel your flight, and where you're flying to. For instance, canceling outside the 24-hour window typically incurs a fee on top of any difference in fare for a new flight. For further details, visit Delta Airlines official website or contact the Delta Airlines cancellation number 1 (800) 221-1212. Alternatively, dial +1-800-865-1848 to get assistance with the flight experts.