Hello Jin628,
Welcome to the community!
Sorry to hear the information provided to you is not accurate. The Fido Roam charges will only incur if your phone uses services -- make or receive a call, send a text message or use data abroad.
While receiving SMS would not incur the roaming charge, it's worth mentioning that the data contained within MMS (incoming or outgoing) would be considered roaming data and charged accordingly. You should note that MMS are not solely restricted to pictures or video messages. Messages with subject headers or group messages etc are also considered MMS. Disabling MMS should prevent that data transfer. Though, it should further be noted that iMessages and RCS messages are sent (and received) as data and not as text messages (SMS).
In order to prevent unintended 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 it is also generally recommended to enable Airplane and/or Flight modes in order to prevent unintended roaming usage. You could then manually enable Wifi when required.
If you did not wish for the other three phones to use their services, the three phones should have their data and roaming data disabled. In addition, it would be recommended to enable Airplane or Flight mode on their devices for the duration of your trip. In theory, Airplane mode should prevent the devices from connecting to cellular towers. However, there have been unverified reports of some devices using services despite that mode enabled. Removing the SIM cards from those devices would ensure they are not able to use Fido services. If you choose to remove the SIM cards, it would be recommended to keep them in a safe place as replacements would likely incur charges. In addition, it might be wise to identify the SIM cards so they may be returned to their proper devices following your trip.
It should be noted that while using Wifi for regular internet access will not incur Fido Roam charges, there seems to be some misunderstanding regarding Wifi-calling. I'm not sure how people have gotten the impression that Wifi-calling does not use the networks. However, that is not true. While the calls and messages do not transmit via cellular towers, they still use the networks via the internet gateway (see image here). The cellular towers and Wifi are merely alternate means of accessing the networks. Calls and messages would not be able to complete or get sent/received without the networks. As such, using Wifi-calling is technically using Fido services. However, they have allowed certain usage to be free from additional charges. All the messages and calls you receive (from anywhere in the world) will be taken from your plan's voice minutes and messaging limits. As well, all Wifi-calling messages and calls you make to a Canadian phone number while abroad won't incur long-distance or roaming charges (see link above).
You should note that if you chose not to remove the SIM cards, it would still be possible to use Wifi-calling and possibly incur roaming charges (even with Airplane and/or Flight mode enabled). I don't think Wifi-calling is possible without the SIM cards as the gateway would need to verify the device to access services.
**edit** Since you are travelling to the US, are you aware their providers have shut-down their '3G' networks (see here). In order to make/receive calls in the US, you would need to ensure your device and plan support voLTE**
Hope this helps 😀
Cheers
Hello @jin628,
How exactly will you be disabling the SIM?
Another option you have and it's what I do is to opt out of the Roam Like Home you can also put a roam block on the line and the device would not connect to any other network, I've had this for many years and never had an issue. Even the WiFi calling would not work when a roam block was applied and I tested this.
Hello again,
If that setting completely disables the SIM then yes, it should act the same as removing the SIM card. However, there are unfortunately no regulations regarding how manufacturers implement the functionality of the settings in their devices. There have been instances where device settings do not behave as customers expect.
For example, as mentioned above, one would believe that disabling data and roaming data should prevent the device from using any data. Yet, some devices seemingly allow some data usage despite those settings disabled.
There have also been instances where some manufacturers don't completely disable a secondary SIM in devices with dual-SIM functionality....
The mobile providers only know usage. They do not know what settings may or may not have been enabled on a customer's device. If there is usage occurring when customers do not believe their devices should be able to do so, that usage would still incur charges. Customers would need to know how their devices behave abroad.
To clarify slightly on what Kapable-K mentioned above, you can request to opt-out of Fido Roam. In doing so, any usage would be on a pay-per-use basis. You can view those rates here. Altenatively, you can also request a roaming block on those lines. As they note, that block should prevent any roaming on those lines. 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 be clear as to which option you choose 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).
Hope this helps 😀
Cheers
@jin628 technically that should do the trick, personally I never rely on software to stop service the last thing you want is for the device to enable it for whatever reason.
That's why I put the roam block so if my phone does roam then that is on the carrier, I also have a VPN setup on my home router so if I connect to a WiFi network in another country I can tunnel back to my home and WiFi calling would work and I don't incur any roaming fees for making and receiving calls to Canada.
