KLM's 24-hour rule allows passengers to cancel their booking within 24 hours of purchase for a full refund. This policy applies to all fare types booked directly with KLM. For assistance, contact KLM customer service: From the US: Call + 1-800-250-5034 to speak with a representative.
https://community.expensify.com/discussion/11943/what-is-the-24-hour-rule-for-klm/p1?new=1
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