The two-letter codes on your airline ticket are standardized identifiers for the individual taxes, airport fees, and carrier surcharges bundled into your fare. Here is a list of the airline tax codes you are most likely to see, what each one funds, and which ones you can get back if you cancel.
Look for a section on your e-ticket receipt labeled “Tax,” “Tax/Fee/Charge,” or “Taxes and Carrier-Imposed Fees.” It sits between the base fare and the total. Each line shows a dollar amount next to a two-letter code. A simple domestic round trip might show four or five codes. An international itinerary with connections can show eight or more.
Domestic US Tax Codes
Four codes appear on nearly every ticket for travel within the United States.
US — Federal Excise Tax. A 7.5% tax on the base fare, collected under the Internal Revenue Code and deposited into the Airport and Airway Trust Fund, which pays for FAA operations, air traffic control, and airport infrastructure.1Office of the Law Revision Counsel. 26 USC 4261 – Imposition of Tax
ZP — Flight Segment Tax. A flat fee applied to each domestic segment (each takeoff and landing). The statutory base is $3.00, adjusted annually for inflation; the current amount is $5.30 per segment.1Office of the Law Revision Counsel. 26 USC 4261 – Imposition of Tax
AY — September 11th Security Fee. A flat $5.60 per one-way trip, collected by the airline and sent to the Transportation Security Administration for aviation security. The round-trip maximum is $11.20. A long enough layover can split a journey into separate one-way trips, each triggering its own charge: four hours or more on domestic connections, more than four hours on international ones.2Transportation Security Administration. Security Fees
XF — Passenger Facility Charge. Up to $4.50 per segment, kept by the airport where you board to fund FAA-approved projects like runway work, terminal expansions, and noise mitigation. You can be charged a maximum of two PFCs on a one-way trip or four on a round trip, capping the total at $18.3Federal Aviation Administration. Passenger Facility Charge (PFC) Program
These stack up on connecting itineraries. A round trip with one connection each way has four segments, so four ZP charges ($21.20) and potentially four PFCs ($18.00) before the excise tax touches the base fare.
International Arrival and Inspection Codes
Flights that begin or end in the United States add a separate set of flat-dollar charges. The 7.5% excise tax was designed for domestic travel, so Congress created parallel taxes for international itineraries.
US on international tickets represents a flat per-passenger tax rather than the 7.5% rate. The statute sets it at $12.00 with annual inflation adjustment from a 1998 baseline; check your receipt for the current figure.1Office of the Law Revision Counsel. 26 USC 4261 – Imposition of Tax
Three more codes cover federal inspections when you arrive from abroad:
XA — APHIS User Fee. Covers agricultural inspections by the Animal and Plant Health Inspection Service, including baggage screening for prohibited food, plant material, and animal products. Currently $3.84 per passenger, adjusting annually through fiscal year 2028.4Animal and Plant Health Inspection Service. International Air Passenger Fee
YC — Customs User Fee. Funds processing through U.S. Customs and Border Protection. For fiscal year 2026, the commercial aircraft passenger arrival fee is $7.39.5Federal Register. Customs User Fees To Be Adjusted for Inflation in Fiscal Year 2026
XY — Immigration User Fee. Covers immigration inspection at ports of entry, including document verification and admissibility checks. Set by statute at $7.00 per passenger.
XA, YC, and XY only appear on international arrivals. A purely domestic round trip will not show them.
Foreign Government Tax Codes
When your itinerary touches other countries, those governments impose their own charges with their own two-letter codes. Codes and amounts depend on the country’s tax laws, so there is no universal list.
The GB code is the United Kingdom’s Air Passenger Duty. Rates depend on distance band from London and class of travel. For April 2025 through March 2026, the reduced rate for economy flights within the UK is £7, while economy flights over 5,500 miles reach £94. Premium cabin rates go higher: the standard rate to a Band C destination is £224, and the higher rate for large private aircraft is £673.6GOV.UK. Air Passenger Duty Rates From 1 April 2025 to 31 March 2026
The UB code is a separate UK charge, the Passenger Service Charge, which covers terminal facilities and ground handling at UK airports. UB revenue stays with the airport operator, unlike GB, which flows to the national treasury. Germany, Japan, Australia, and many other countries assign their own distinct codes to departure taxes, security levies, and airport improvement fees.
YQ and YR: Carrier Surcharges
Not everything in the tax box is a tax. The YQ and YR codes are surcharges filed by the airline itself, not collected for any government. Airlines use them to price in costs like fuel volatility and insurance without changing the base fare filed in booking systems. Because they sit in the same section of the receipt as government taxes, they are easy to mistake for mandatory fees.
The distinction matters. On long-haul international flights, YQ and YR sometimes exceed the base fare. A $400 base fare with $600 in carrier surcharges is not unusual on certain routes. The airline sets these amounts at its discretion, so when comparing tickets across carriers for the same route, government taxes should match and the price difference tends to hide in YQ and YR.
Which Codes Are Refundable if You Cancel
If you cancel a non-refundable ticket and forfeit the base fare, some codes still come back and others do not. Border-crossing inspection fees refund because the inspection never happened; domestic transportation taxes generally do not.
Refundable on unused non-refundable tickets:
- AY — September 11th Security Fee
- XA — APHIS User Fee
- XY — Immigration User Fee
- YC — Customs User Fee
Not refundable on unused non-refundable tickets:
- US — Federal Excise Tax (domestic and international)
- ZP — Flight Segment Tax
- XF — Passenger Facility Charge
YQ and YR are also non-refundable on non-refundable tickets, since they are not government taxes.7American Airlines SalesLink. Tax – Non-Refundable Tickets – Refundable US Tax Codes
If the airline cancels your flight or significantly changes it, DOT rules entitle you to a full refund of the ticket price including all taxes and fees.8US Department of Transportation. Refunds
Taxes on Award Tickets
Miles cover the base fare but not the taxes and fees. AY, XF, ZP, and any international taxes appear on award tickets at the same rates as paid tickets. YQ and YR can hit award tickets hard: some carriers add hundreds of dollars in fuel surcharges even on flights booked entirely with miles, which is where the “free” ticket stops being free. Comparing award costs across programs and routings is the main defense.
One code you will not see on an award receipt is the 7.5% US excise tax. It is paid upstream, at the point where the airline sells miles in bulk to a bank or credit card loyalty program, rather than at redemption.1Office of the Law Revision Counsel. 26 USC 4261 – Imposition of Tax
Alaska and Hawaii: A Quirk in the Tax Math
Flights between the continental United States and Alaska or Hawaii cross Canadian airspace or open ocean, technically outside U.S. territory. For the 7.5% excise tax, only the portion over U.S. soil (or Alaska/Hawaii) is taxable, and the tax is prorated by the ratio of domestic miles to total miles, which drops the effective rate below 7.5%.9eCFR. 26 CFR 49.4262-2 – Exclusion of Certain Travel
The flat international departure tax also applies to the overwater or over-Canada portion of these routes, but at half the standard rate and only on departures. The statute sets it at $6.00 (versus $12.00 for standard international flights), with the same inflation adjustment from a 1998 baseline.1Office of the Law Revision Counsel. 26 USC 4261 – Imposition of Tax
Flights entirely within Alaska or entirely within Hawaii do not get this split treatment. They are taxed as standard domestic flights with the full 7.5% excise rate and regular segment fees.