U.S. Federal Segment Fee
Per-segment fee applicable to flights within the continental United States.

U.S. Excise Tax (aka U.S. Domestic Transportation Tax; U.S. Ticket Tax)
Percentage of fare; applies to flights within the continental United States or Canada/Mexico 225-mile buffer zones.

U.S. Domestic and International

Travel Facilities Tax 
(aka Alaska/Hawaii Ticket Tax)
Applies to certain flight segments to or from Alaska or Hawaii.

U.S. International Transportation (Arrival/Departure) Tax
Applies to all flights arriving in or departing from the United States, Puerto Rico, or the U.S. Virgin Islands.

International Taxes and Government or Airport-imposed fees
Various foreign taxes, inspection fees, and security charges typically excluding airport departure taxes

U.S. Animal and Plant Health Inspection Service (APHIS) Fee
Applies to all flights originating abroad, except Canada, and landing in the United States, Puerto Rico, or the U.S. Virgin Islands.

Passenger Facility Charge (PFC)
Variable fee based on airport for facilities improvement. A maximum of 4 charges per itinerary applies

September 11th Security Fee 
(aka U.S. Passenger Civil Aviation Security Fee)
U.S. government-assessed fee of $2.50 per U.S. enplanement per ticketed journey for security costs not to exceed $5.00 one-way or $10.00 round-trip.

U.S. Immigration and Naturalization Fee
Applies to international arrivals to the United States, Puerto Rico, or the U.S. Virgin Islands.

U.S. Customs User Fee
Applies to international arrivals from outside of the U.S. Customs territory.