Prepaid doesn't work. When there is a Swisscom SIM or eSIM on the phone, you get the option to enable a plan for the child's watch as expected. When you log into the Swisscom portal via the Watch app, on a prepaid plan you get a limited Cockpit that does not allow eSIM selection for the child's watch. You are only allowed to choose the watch eSIM with a regular subscription plan, as far as I can tell.   This makes it impossible to use the blue Kids Watch plan unless the parent's iPhone is on a full Swisscom subscription.   @Thengonau12 wrote: My child has an Apple Watch SE with LTE - managed with Apple Watch Family Setup on my iPhone (which is not on Swisscom). I've just purchased the blue Kids Watch subscription. How do I install the eSIM on my child's watch? The QR code setup path appears to install the eSIM on the phone itself.   ... View more

When selecting "Cellular" for the child's watch, the "Set up Cellular" option is disabled, and the text says that the phone's account is not eligible to enable cellular on the watch. I will contact Swisscom to try and resolve this. ... View more