KLM Airlines offers a Business Class cabin on long-haul international flights with lie-flat seats, premium dining, lounge access, and enhanced service. Amenities include extra legroom, priority boarding, airport assistance, and complimentary drinks. Passengers, If you want to Upgrade to KLM Business Class, you can visit the Airlines Group Travel or contact a KLM reservations agent 866-434-0320 or +1-888-609-1015 (OTA Skip-Waiting). KLM Business Class aims to provide superior comfort in the air.