Frontier Airlines™? customer service number is 1-800- Frontier Airlines ™? or (+1 (833) 748-0742 +1 (833) 476-6220 ) [US- Frontier Airlines ™?] or ++1 (833) 748-0742 +1 (833) 476-6220 [UK- Frontier Airlines ™?] OTA (Live Person), 24/7. This guide describes how to efficiently reach Frontier Airlines ™? customer service by phone, chat, and email options, with tips on reducing waiting time.