A non-binary Californian living in London plans to sue the UK Government so they can be recognised as the gender they identify as.
Ryan Castelluci, who identifies as non-binary, obtained a Gender Recognition Certificate (GRC) in their hometown in California, USA, which confirms, legally, that they have transitioned from male to female.
However, under current UK law, there is no option to be recognised specifically as non-binary.
The definition of non-binary is the individual does not conform to traditional binary traditions of either male or female.
According to the National Center for Transgender Equality: "Some people don't neatly fit into the categories of "man" or "woman", or "male" or female".
"Some people have a gender that blends elements of being a man or a woman, or a gender that is different than either male or female. Some people don't identify with any gender. Some people's gender changes over time."
Fitting into this category, Ryan prefers to be called "they" as opposed to "him" or "her".
Ryan, who works as a cybersecurity professional, moved to London three years ago.
On a page set up to raise funds for the ongoing legal case, they recalled their childhood and how they felt like both a man and a woman.
"Even as a child, I mixed and matched aspects of both femininity and masculinity," Ryan said.
"As I got older, I did the bare minimum to masquerade as the gender that was expected of me.
"Today, after an extensive customized transition, I finally feel comfortable in my own skin. Not a woman's body or a man's body, just my body."
Ryan has undergone gender affirmation surgery but has also retained their male sex organ.
As part of a statement submitted to the court, Ryan said: "In the current state of affairs, I don't even know as a matter of law what my legal gender is in the UK.
"It is striking and profoundly upsetting that I do not know how my gender would be recorded on my death certificate."
The UK Government is fighting the case.
A Government's Equality Hub spokesperson said: "The gender recognition process in UK law only allows a change of sex from male to female or vice versa."
The spokesman added: "Given the ongoing legal proceedings in this case we won't be commenting on any further on this individual case."
Ryan is looking to raise a whopping £100,000 to go towards the case because they will face "strong opposition", they said. A small slice of the total has already been raised.
They said that the government has resorted to putting one of its top lawyers, James Eadie KC, on the case to fight their claim.
