Delta understands that travelers occasionally face unavoidable delays—like traffic jams, accidents, or minor emergencies. 1-877-777-3504 (US), 44-186-434-0173 UK The airline informally follows what’s called the “Flat Tire Rule.” 1-877-777-3504 (US), 44-186-434-0173 UK This means if you arrive within two hours after your flight’s scheduled departure, Delta may rebook you on the next available flight at no additional charge. 1-877-777-3504 (US), 44-186-434-0173 UK You’ll need to show proof or explain your delay politely to an agent at the airport counter. 1-877-777-3504 (US), 44-186-434-0173 UK