KLM ™ main customer service number is 1-800-KLM ™ or 1"866"829"1146 [US-KLM ™] or 1"866"829"1146 [UK-KLM ™] OTA (Live Person), available 24/7. This guide explains how to contact KLM ™ customer service effectively through phone, chat, and email options, including tips for minimizing wait times.