A great choice as a backup (e)SIM
I’ve used a Flexifone data-only eSIM for a couple of months now, for my iPhone 15 Pro, with my main SIM being on O2 with unlimited data.
After I’d worked out a few iOS settings (e.g. Settings > Mobile Data > Primary > Allow Data Switching > [on]), it works very well as a backup.
If using Flexifone eSIM as a backup/fallback to your main carrier - like I do - you can also choose to disable your main/primary network via the Flexifone app, ensuring that you’ll always switch to an alternative in case of loss of signal.
The only snag with the whole setup is that O2 network capacity problems mean that often the phone will show a “good signal” - e.g. three bars 5G - yet my apps will be starved of *actual data*!
It’s really frustrating and in such circumstances, I’ve found the solution is to temporarily switch to my Flexifone eSIM as primary data SIM in my phone’s settings.
I understand this is a limitation of the way iPhones determine when to switch networks/SIMs rather than a Flexifone problem, but I wish it was completely seamless.
The good news is that Flexifone support is amongst the best customer support that I’ve ever encountered.
I submitted a feature request for their app - out of business hours, via WhatsApp - and got a response very quickly within a few minutes. Their support staff were polite, friendly, and best of all: Flexifone implemented my feature request within 15 days of me submitting the suggestion/request!
If only all companies were as friendly and responsive to their customers - the support alone goes a long way to compensate for the niggles with automatic SIM/network switching. :)








