KLM has a sizable client base and utilizes Washington Dulles Airport regularly. So if you ever need to know something, like "How do I contact KLM at Washington Dulles Airport?" do not hesitate to ask. Don't be hesitant to inquire, please. The KLM Washington Dulles Airport phone number is +1-802-610-2076, and an agent will be assigned to you to handle your concerns if you have any issues with flight timing, terminal number, baggage allowance, or any other pertinent issues.