Extra Frontier Airlines Baggage Fees, are applied when the baggage is more than the required weight. If you are carrying carry-on baggage and one checked baggage then they will charges you just as small a fee while it is the opposite while when you carry extra baggage to Frontier airlines baggage policy is fixed and are strict. Frontier airlines always follow their policies strictly and do not let anyone break them. You can check the weight of your baggage before going out of the home.