Hello RomainD,
Welcome to the community!
Sorry to hear of your mother's passing. Please accept our heartfelt condolences.
I understand the charge for unintended roaming usage is concerning. Most plans include Fido Roam. With Fido Roam, if your WhatsApp call used cellular data, that data would have been taken from your regular data allotment. It's possible that call just triggered the Fido Roam charge for one day ($15). However, as FidoAllan alluded to below, if the call extended beyond 11:59:59 PM (ET), a second daily charge could have incurred.
In order to avoid roaming charges, it is generally recommended to disable data and roaming data. However, you should note that disabling those settings does not prevent roaming for voice and messaging. In addition, some manufacturers might allow some data usage to occur despite those settings (see here). That's why FidoAllan also recommended to enable Airplane and/or Flight modes in order to prevent unintended roaming usage. You could then manually enable Wifi when required.
That said, those settings may apply to both SIMs, limiting the utility of the other SIM card. Unfortunately, dual-SIM functionality is not standardised. There may or may not be any way to completely disable one of the SIM cards. How the device manages dual-SIMs would be determined by the manufacturer.
If possible, removing the Fido SIM card would be the only way to ensure there is no usage of Fido services. You might also consider placing a roaming block on your line. It should be mentioned, though, as far as I am aware, that roaming block would also prevent devices from accessing extended coverage in Canada (Fido-EXT). You would need to ensure they block roaming and not opt-out of Fido Roam as there have been instances where people have thought they blocked roaming (no usage abroad) but only had opted-out of Fido Roam (pay-per-use abroad).
May your mother rest in peace ❤️
Cheers
Hey @RomainD,
I'm really sorry to hear about this and I would like to offer you my sincere condolences.
To avoid Fido Roam fees, you have to make sure that your mobile/roaming data is turned off at all times, to not send texts and to not make/receive phone calls.
You can also put your phone on airplane mode, turn off the device or remove the SIM (at all times as well).
If you use it, you will be charged for using talk, text and data each day until 11:59:59 p.m. (Eastern Time) regardless of which time zone you are roaming in.
For more info: https://www.fido.ca/consumer/mobile/travel
If you have any questions when the bill become available, don't hesitate to contact us!
