Your Superdrug Mobile SIM may not work abroad unless you make a one-off change to your phone settings. Here's a short video that shows how to change your settings.
Follow these steps to get your phone ready:
Go to ‘Settings’
Open ‘Mobile Data’
Open ‘Mobile Data Network’
Change the Mobile Data APN to: superdrug.net
Change the MMS proxy to 188.8.131.52
That’s the only thing you have to change. If there’s any information in other fields, you can leave it as it is. It should look like this: