After all the fun and games getting the Apple Watch on O2 I was hoping for a happy ending. But this didn’t happen because although we could quite happily make phone calls with the device all the network and SMS features were broken. I was thinking for a while that I’d have to ring up and they’d try to sell me another watch. Wah.
But the good news is that the fix was quite simple. I opened the Apple Watch app on the connected iPhone and then went to the Mobile Data tab. This shows you the data used by the watch. Just as the phone was heading to the page it displayed a “Carrier settings update” message and offered me the chance to confirm. After doing this the watch seems to work fine with SMS and mobile data. So, if you’ve bought one (or even several) Apple watches from O2 and can’t get the data to work you might like to try this.