U.S. airlines are now required to follow a new US airlines gender marker rule for International travel. The change require them to list passengers using only the binary of ‘M’ (male) or ‘F’ (female) when sending flight data to Customs and Border Protection (CBP), even if a traveller’s passport gender marker shows ‘X’. This is part of a broader federal travel policy update which took effect October 12 after a 90-day compliance period.
Airlines Directed to Use Only ‘M’ or ‘F’
In July 2025, CBP instructed airlines and other travel carriers that their Advance Passenger Information System (APIS) would only accept ‘M’ (male) or ‘F’ (female) in the sex field for international flights.
Following a 90-day grace period, the policy went into full effect on October 12, 2025. Any submissions containing other characters now result in a system error.
Under the new US airlines gender marker rule, carriers must submit only ‘M’ or ‘F designations when providing passenger information to Customs and Border Protection for international flights, even if a traveller’s passport gender marker is listed as ‘X’. Passports already issued with an ‘X’ marker remain valid travel documents, protected under a June 2025 federal court injunction that reaffirmed their legitimacy despite the policy change.
However, for ‘non-gender-conforming’ travellers the ‘X’ option is no longer available for new or renewed passports following a January 2025 executive order that revised federal travel policy standards to recognise only male and female identifiers.
CBP confirmed in a statement that travellers with valid U.S. documents “are being processed as they were previously.” The agency also said applicants for Trusted Traveler Programs must now select either male or female when completing forms.
Court Order Keeps ‘X’ Passports Valid
The directive follows Executive Order 14168, titled ‘Defending Women From Gender Ideology Extremism and Restoring Biological Truth to the Federal Government’, signed January 20, 2025 by President Donald Trump, which sought to remove recognition of non-binary gender markers from federal records.
In June, the U.S. District Court for the District of Massachusetts ruled in Orr v. Trump that the government must continue issuing passports with ‘X’ markers for certain applicants.
The State Department suspended all applications for passports with an ‘X’ passport gender marker in January 2025, following the executive order. However, a federal court injunction in June temporarily allowed eligible applicants, including those renewing or updating documents, to continue using the ‘X’ option. The order remain in place while the government appeals the decision and seeks to reinstate its updated travel policy limiting gender markers to two options.
Attorneys and Travellers Seek Clarity
Attorneys and ‘non gender conforming’ travellers said the change has created uncertainty about how it will be applied at airports.
Andy Izenson, senior legal director at the Chosen Family Law Center said:
“It’s too soon to know how this will work in practice.”
Dr. July Pilowsky, a U.S. citizen residing in Spain who uses he/they/she pronouns, said they may use their Chilean passport, which does not include an ‘X’ option, has stated they may use their Chilean passport to avoid potential issues when traveling to the U.S., as it does not have the “X” gender marker.
The change underscores ongoing tension between federal identification rules and newly introduced gender definitions. For airlines and border agencies, it poses logistical challenges as systems adjust to meet new reporting standards and process passenger data accurately. As courts and agencies refine the travel policy, travellers may face a transition period before procedures are fully streamlined. Read more on passport policies here.
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