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 for roaming:
Go to ‘Settings’
Tap ‘More…’ under ‘Wireless & Networks’ or 'Connections'
Open ‘Mobile Network’
Open ‘Access Point Names’ - If you don’t have any access point you’ll need to create a new one and skip to step number 7.
Open ‘Edit Access Point’
Change the APN to: superdrug.net
Change the MMS proxy to 18.104.22.168
That’s the only thing you have to change. If there’s any information in other fields, you can leave them as they are!
It should look like this:
If you find you're not able to change the APN you'll need to add a new one. The settings are here: