How strict is Frontier about pet carrier size? Frontier Airlines has strict size requirements for pet carriers allowed in the aircraft cabin. Soft-sided carriers must be no larger than 18 long x 14 wide x 8 high to fit under the seat. Larger hard-sided kennels must go as checked baggage. Carriers that exceed Frontier's size limits will not be permitted. If you need more details about Frontier Pet Carrier Size visit the Airlinespetpolicy site or contact the helpdesk for your live assistance. 🌎Website: https://www.airlinespetpolicy.com/airlines/frontier-airlines-pet-policy.html #frontierpetcarriersize #frontierairlinespetpolicy #frontierairlinespet #frontierairlinespetfee #frontierairlinespetcarriersize #frontierairlinespettravel #frontierairlinespetincabin #frontierairlinespetcarrier