British Airways is the latest international airline to announce it will offer a non-binary gender option when booking tickets for passengers who identify outside of male or female.
The British carrier's announcement follows similar moves from major US airlines, as well as Air New Zealand, which recently said it was looking to introduce more gender options.
The change has been welcomed by LGBTQ groups, who say it will help make travel less stressful for trans, intersex and non-binary passengers, as well as those who don't wish to disclose their gender.
A spokesperson for British Airways told MailOnline Travel: "We know how important it is for all of our customers to feel comfortable and welcome no matter how they self-identify.
"We are working to change our booking platform to reflect this."
Air New Zealand said this week it was "exploring how we can introduce non-binary gender options across our various digital environments".
The national carrier's plans could put its booking practices in line with existing passport options for Kiwi travellers.
The New Zealand passport allows people to state their gender as male, female or "X" (indeterminate/unspecified), without the need to change their birth certificates or citizenship records.
Julia Ehrt, of the International Lesbian, Gay, Bisexual, Trans and Intersex Association, told Reuters the organisation welcomed the changes from airlines.
"Persons presenting as gender non-conforming or trans persons who might not have been able to change their name or gender markers in passports regularly have serious challenges in travelling.
"That can range from being challenged about your gender marker or first name upon check-in or at security, through to outright denial of being able to board a plane."
Two air trade groups – Airlines for America in the USA and the International Air Transport Association (IATA) – have recently approved new international best-practices to suggest how travellers using "non-binary IDs" should be accommodated.
Five of the biggest US carriers - American, Delta, United, Southwest and Alaska airlines – have said they planned to implement the suggestions.
The Lufthansa Group, which owns Lufthansa, Swiss and Austrian Airlines, also told Reuters it was "taking the implementation of additional gender options into consideration".