Enby they/them pronouns - what's the law on this?

While being non binary may not be protected under gender reassignment it would be covered under beliefs . As the judge said in the forstater hearing you cannot use your beliefs to create a hostile environment & that the ruling didn't set a legal precedent.
Surely you have more important things to do

Bullying an employee because they're non-binary isn't heroic, or making a stand against anything.

It's really easy to use they/them pronouns, and deeply unprofessional to target someone for being different. They aren't posing, just being themselves.

If your main concern is singling out, targeting, humiliating, disrespecting & bullying this person (which is what refusing to use their pronouns is) then you can expect a summons from HR. End of. Horrible behaviour.

Yes, it has been widely discussed on this thread.

Has anyone mentioned this case yet?

I:d forgotten about it but it is in the field of employment law
https://assets.publishing.service.gov.uk/media/6926ec33a245b0985f0340aa/Haech_Lockwood_v_Cheshire_and_Wirral_NHS_Foundation_Trust_and_others_2401211_2024___2407178_2024.pdf

Ooh that's unfortunate that there's no specific policies its also good news for you as they are watching what's going on in tribunals and have paused to think and are hedging their bets @SirChenjins.
If you are fair and walk the tightrope and the nb woman complains about you or your staff she will get a nasty surprise as it sounds like they dont want to be the next NHS Fife with a Dr Uptons false allegations as a main witness

@SirChenjins if you are concerned that she might bring her whole activist self to work it might be a good idea to check out your works policies on religion, politics and bullying asap.
If your work has a policy of no political campaigns or flags, badges and stickers etc, it would be a good idea to have a copy at hand to show her when you need to have the inevitable discussion about her progress flag etc.
Same for the religion policies for when she starts banging on about gender ideology.
If you have to have conversations about either of these policies and/or pronouns you can almost guarantee that you and/or your other staff will be accused of bullying.
Good luck with this

If you've met them, how do you not know how they want to be referred to? If you've met them and they've not said anything, I'd assume they're ok with she/ her pronouns. I'm still curious what would make you think otherwise.

I cannot remember any of the things you listed. I got to the end of secondary school without learning the names of everyone in my 150ish-strong year group. It took me a whole year to learn all my classmates' names.

Did I mention being autistic? People ADHD often have similar problems, likewise dyslexia.

Saying "they aren't significant efforts" is actually rather ableist.

No.

It doesn't matter how many times I thoughtlessly call Smithy "Mr. Smith" or offer Fatimah a biscuit during Ramadan. I cannot be accused of violating their dignity.

Obviously if I offer the one religious Jewish guy prawn crackers four times a day to wind him up, that's different. But we're not talking about intending to wind someone up by referring to them - not even in their presence! - as "she" instead of "they". Entirely different.

You can't pick and choose parts of the analogy and then call it stupid.

Yes I can. As an analogy it's stupid.

Getting offended because someone offers you a biscuit ONCE would be too sensitive, and would not result in a disciplinary in any sensible organisation, and it should be exactly the same with pronouns - as I literally said " with SHARED understanding that occasionally this might read slightly stilted and sometimes people might forget and shouldn't be penalised."

Repeatedly offering somebody a biscuit after being told they were fasting, and/or saying that fasting for religious reasons was stupid/unhealthy/ridiculous absolutely would be inappropriate and could result in disciplinary proceedings.

Same with the name example. Yes you could choose to keep calling Sadie 'Ms Jones' if you wanted to be excessively formal but the reverse doesn't apply - if she wants to be called Ms Jones and you insist on referring to her by her first name, again, yes, you could get in trouble for it. You can't pick and choose parts of the analogy and then call it stupid.

boss A likes to be addressed as Mr Smith whereas boss B tells everyone to call her by her first name" or "remember how Saoirse's name is pronounced.

I'll go further. It's my choice whether to call boss A as Mr Smith, Bob, or Smithy, and even if boss B tells me to call her by her first name I may well choose not to do so. If I continue to call her Ms. Jones then that's my prerogative, and she would be unreasonable to be offended by it. Saoirse's pronunciation is easy to remember, even if I have to look up her spelling, which I'm quite willing to do, but even if I don't remember or can't be bothered to do either it doesn't rise anywhere close to a claim for harrassment in a tribunal, nor should it.. The whole analogy is stupid and wrong.

If David or Omar are offended by being offered a biscuit, they are too sensitive. And I speak as someone with my own religious observances that I entirely don't expect other people to keep track of.

Ive never known how people take their tea or coffee at work as ive never made anything other than my own at work. But if I had made one wrong I wouldn't have been disciplined for it. That's the difference.

It's no harder than remembering how everyone likes their tea/coffee, or "don't offer a biscuit to David/Anna/Omar because they're dieting/coeliac/observing ramadan" or "remember not to swear or say "for godssake" in front of Mary because she finds it disrespectful" or "don't ask Tom if he had a nice weekend because he's struggling with his divorce" or "Frederick in accounts likes to be called by his full name but Frederick in legal prefers Freddie" or "boss A likes to be addressed as Mr Smith whereas boss B tells everyone to call her by her first name" or "remember how Saoirse's name is pronounced."

Lots of these things might not come completely naturally and you might privately think they are a bit silly and disagree with some of them, but they aren't significant efforts to make.

100% agree this would be the way to go.
Work colleagues aren't your friends or family. You don't have to agree with them about every single thing, or even like them. You can privately think they are complete muppets as long as you manage to engage professionally with them.

Therefore an easy compromise would be that someone who does not want to use pronouns they disagree with solely refers to that person by their name, including in the (comparatively rare) occasions where they need to refer to said colleague in the third person, with SHARED understanding that occasionally this might read slightly stilted and sometimes people might forget and shouldn't be penalised.

It really shouldn't be too taxing for any competent professional to write or say something like "discussed project A with internal legal officer Jane Jones who said xyz. I queried point B and Jane advised abc." Rather than "discussed project A with Jane. She said....."

I read it as someone possibly already in the company, but I guess it could be a completely new starter. I also assumed it has something to do with them adding pronouns to an email signature, as a standard team signature. I suppose the specifics may make a difference, for example if they had them in a signature elsewhere in the company. Although, as others have said, if it’s about emails it may come down to company policy - or the lack of one.

I applaud the OP for having the foresight to investigate a situation before it occurs, to avoid trouble for her team in the future. If I were her manager, I'd give her a bonus.

I took this to read that you hadn't yet met them, as you said that they were new to your team.
Although I can see that it was rather ambiguous as it could just mean you don't really know them at all and instead are just making assumptions based on "suspicions".

New person coming into my team who I think may want others to use they/them

if my suspicions are correct and she starts bringing her whole enby self to work

That was my thought too. That they haven't started there yet, so on what grounds are you basing all this on?!
You haven't even met them yet!
Are you going by looks, and what you "expect" a person who looks like "that" to do/say/be?