Perhaps when you buy an eSIM iD plan for your Apple watch, @Nico Kearns.

https://www.idmobile.co.uk/sim-only-deals 

Hi @Nico Kearns 

Unfortunately at this time we do not officially support usage of an eSIM in an Apple Watch, sorry.

Tom

Is this something ID mobile are looking to be able to provide? 

I was an id customer for years. Left due to esim. Then i leave and they bring out esim lol. But just esim. Not data version we need for watches so im ok. But im hoping to come back as soon as its available. My mrs contract has ended and told her to use id as i will be back one day also. But this one missing feature is a killer. Such a shame. Loved being a customer here. Soon as its available. Let me know. We will both join up. 

Hi there @Arnis65, this is certainly something we may look to offer in the future, but unfortunately, I haven’t got a definitive answer to give you on this I’m afraid or any guarantee or time-frame regarding this.

We’re always looking to improve, and it’s certainly a feature we’re aware of, so it’s definitely a possibility in the near-future I’m sure.

@RFGrinch, we’d of course welcome you back anytime with open arms!

Kind regards,

Tyler

I too have left ID due to no eSim for watches.

They use Three’s network and three support it. 

ID have made a conscious choice not to support eSim for watches, and so have made a conscious choice to part ways with many loyal customers, specifically customers who tend to spend a lot of money on connected devices.  This nonsense is a deal breaker. Not supporting wearable tech means ID is still stuck in pre-2015 era and is taking it’s customers for granted for the last 9 years.  It’s clear they’re not going to change so I won’t recommend them to anyone anymore. If they can’t be trusted to implement a hardware standard which is now over 9 year old, what is the point in staying with them? What will they not support next? Is it really worth paying a couple of extra quid less per month to be constantly limited in what devices you can buy? Of course not, that’s a ludicrous suggestion.  Move networks.

I’m now with Three, cutting out the middle man. Works great! And they get an extra £6 per month out of me ID didn't want.