What is the 24 hour rule for KLM?

https://central.xero.com/s/question/0D58V00009CW5BtSAL/official-klm-what-is-the-24-hour-rule-for-klm

Klm 24-hour rule lets passengers cancel their booking within 24 hours of purchase without a penalty. For more information, contact. This policy provides flexibility, particularly for flights departing from the US. Klm customer service contact number and klm airlines name change policy.