Airlines for America, the industry trade group representing the country’s largest airlines, will add new gender options in order to accommodate non-binary passengers who have “X” on their IDs, The Daily Beast can confirm.

Airlines for America, or A4A, told The Daily Beast that it “recently approved a new international standard that will allow for ‘unspecified’ and ‘undisclosed’ as options in addition to ‘male’ or ‘female’”—a decision made in conjunction with members of the International Air Transport Association, or IATA, which represents carriers worldwide.

“The updated procedures are effective June 1, 2019,” A4A said.

Delta, which left A4A in 2015, separately confirmed to the Daily Beast that the airline is “planning to offer a non-binary gender option during the booking process” as part of their “ongoing efforts to accommodate the needs of diverse customers throughout our business.”

A4A members—which include American Airlines, Alaska Airlines, United, JetBlue, and Southwest—will still have to individually update their online booking processes, which currently only allow passengers to select “male” or “female” from drop-down menus.

But A4A told The Daily Beast that its member airlines are “committed to making these changes to their reservation processes to account for non-binary IDs while ensuring continued compliance with U.S. and foreign government requirements that passenger data match the identification used for travel.”

The change in the A4A standard represents a major victory in the movement to add a non-binary gender option to government ID. Currently, five states—Oregon, California, Colorado, Arkansas, Minnesota— and Washington, D.C. allow non-binary people, who identify neither as strictly male or female, to get driver’s licenses with “X” as a gender marker rather than “M” or “F.”

But non-binary people who already have “X” driver’s licenses told The Daily Beast that they still have to choose either “male” or “female” when reserving flights—and they often take an alternate form of ID to the airport as backup.

“For now, I carry my passport with me in addition to my driver’s license just in case,” Alon Altman, a non-binary Google employee, told The Daily Beast.

That’s in line with what the National Center for Transgender Equality recommends for passengers who have gender-neutral ID. In a 2017 FAQ, the transgender rights advocacy group wrote, “It is ideal to bring an ID to fly that has a gender marker that matches the gender you submitted to the airline.”

Still, several non-binary people contacted by The Daily Beast reported no issues showing their new “X” driver’s licenses to Transportation Security Administration agents.

“I have used it at TSA and [while] checking in to a flight,” said Altman. “They didn’t even seem to notice the gender marker.”

“I travel at least once every month and haven’t had any issues,” non-binary psychologist Dr. Liz Powell told The Daily Beast.

“I always worry about it when I fly, but so far no one has even acknowledged it, and everything’s gone smoothly,” said one non-binary D.C. resident. “I’ve only had it since around April though, so who knows what the future will bring.”

Currently, non-binary people with “X” driver’s licenses said that, when booking flights, they tend to either select the sex they were assigned at birth or the gender listed on most of their other forms of ID.

A TSA spokesperson told The Daily Beast that when airlines send passenger data to the agency’s Secure Flight system for prescreening, “the system accepts Male (M), Female (F), or any other gender character included on a valid government-issued ID.” That is consistent with what the TSA told the LGBT media outlet Into in November 2018.

Given that several forms of “valid government-issued ID” now allow “X” in the gender field, TSA has not been the obstacle preventing non-binary bookings for at least four months now. (TSA told The Daily Beast that what’s not allowed is for the gender field to “be left blank, contain a single space, or contain the word ‘UNKNOWN.’”)

Last November, A4A told Into that there was “ongoing work among A4A carriers to make changes to their reservation processes to account for non-binary IDs”—but would not comment on the National Center for Transgender Equality’s claim that guidelines on the issue would be implemented in June 2019, as The Daily Beast can now confirm.

Several major airlines did not immediately respond to The Daily Beast’s request for comment as to when non-binary passengers who have “X” on their government IDs could expect to be able to reserve flights without having to select either “male” or “female.” (American Airlines referred to A4A.)

“ The rollout of the new A4A guidelines this June should clear the path for airlines to implement changes that will finally allow non-binary travelers to pick an 'X' ”

Southwest said that they were “currently investigating solutions and the technical requirements needed to provide our customers non-binary gender marker options during the booking process” and that they “look forward to having more details to share in the future.” (That represents a step forward from last year, when Southwest reportedly did not respond to Into’s request for comment.)

United and Alaska previously told Into that they were “investigating solutions” and “exploring options,” respectively.

But the rollout of the new A4A guidelines this June should clear the path for airlines to implement changes that will finally allow non-binary travelers to reserve flights without making a binary choice.

“U.S. airlines value a culture of diversity and inclusion, both in the workplace and for our passengers, and we work hard each day to deliver a safe, secure and enjoyable flight for all travelers,” said A4A.

Update 2/15/19 2:00 PM: United Airlines told The Daily Beast in a statement that they will “begin offering our customers the ability to select the gender with which they most closely identify during the booking process,” including a non-binary option.

“Beginning in the coming weeks, customers will be able to identify themselves as M(ale), F(emale), U(undisclosed), or X(unspecified), corresponding to what is indicated on their passports or ID,” a United spokesperson said. “Also, customers who do not identify with a gender will have the option of selecting ‘Mx.’ as a title.”

Alaska Airlines also sent a statement to The Daily Beast, indicating that they will introduce changes for non-binary passengers: “As part of our values of having a culture of inclusion for all, we are planning to implement a non-binary gender option for guests to select in the booking process.”