I'm a Swim Team Manger, and we have had some advice from Stonewall via Swim England
The term trans describes some people’s ‘gender identity’. We are assigned a sex at birth (male or female) but our gender identity is our
internal sense of our gender (male, female, something else). Our gender identity may, or may not, sit comfortably with the sex we are assigned at birth.
As a club administrator or activity coordinator, you are legally obliged
to protect against the discrimination and harassment of people on the
protected characteristics of sexual orientation and gender reassignment
So it can be argued that self ID seems to be protected characteristic, the same as sex.
In most situations, someone being trans won’t mean anything needs to change at all. The goal should be a positive experience for everyone at your club or session so be clear on what you are doing to support transinclusion from the outset.
The idea that you need to ask people to prove their gender when they join or start an activity is unnecessary, as well as off-putting for lots of trans people
"So, Miss 6ft 2in bearded swimmer, why are you coming in to change with my Under 12 girls team?"
-"Don't ask me, I'm a Lady!!!"
