Dual Sim overseas

[yeshivabachur613]

Any geeks out there??
I’ll start from the very beginning.
I’m on Verizon. if I put my phone on airplane mode and only connect to wifi then the phone works perfectly. All incoming and outgoing calls and incoming outgoing texts work regularly (even without message plus) as if I’m connected to a Verizon tower.
I’m in israel now and I have a hot mobile SIM card and a dual sim android phone. What I want to do is (don’t know if it’s possible on android), is to put both sims in the phone and have the Verizon sim on airplane mode and then have my hot mobile data be the “wifi” connection for the Verizon sim (hence, free Verizon “roaming” [although its over a data connection} in Israel).
Apple has this concept (though it has its problems and I’ll explain them soon) so I know the concept exists.
The way it works by Apple is that if for example sim 1  doesn’t have a stable connection it will make a “wifi call” over sim 2’s data connection. (One physical sim and one esim)
Problem with this is that the sim has to be on so when you go to a country that has Verizon roaming the Verizon sim will roam and not use the other sim’s connection. If you happen to be in a no coverage area for Verizon roaming but have a good hot mobile connection then it will make a “wifi call” over hot mobile.
Android lets you force a sim into a specific network so the trick for this issue would be to force the Verizon sim into a network that Verizon doesn’t roam on and then it will use the hot mobile sim as its connection. Problem is Apple doesn’t have the option to choose a network.

Moral of the story is that I want to use a dual sim android phone and have the Verizon sim “wifi” off of the hot mobile data connection. Is this possible?
Also if anybody knows how to make this work on an iPhone, that would be great! (For iPhone the concept is there as I explained I just need a fix to the problem I mentioned)

[JudahMcB]

I'm not entirely clear what issue you are trying to solve on Android and what issue on iphone. Same issue?

For Android (for sure Samsung, maybe others too) it can't be done with phones sold in the US market. I couldn't get it to work on my S21 on a recent trip to Europe even after playing with carrier settings like you described. Something to do with US carriers disabling it so they can gouge you for a $10/day international travel plan, though you won't see anything official about this. Supposedly it works on non-US dual sim phones. US phones are missing the "backup calling" feature.

It does work on iPhones. You need to disable roaming on the Verizon sim and enable "allow cellular data switching" in the roaming settings. See https://support.apple.com/en-us/HT209044. I don't have an iPhone so I haven't tried this but supposedly it works.

[yeshivabachur613]

It’s 2 different issues. The iPhone issue should be solved by doing as you described though I never got it to work…
The android issue it sounds like you get what I’m trying to do. It’s a real shame they don’t let. I have a uniherts titan pocket. I wonder if it should work…

[yeshivabachur613]

Just tested on iPhone with Verizon physical sim and an Israeli esim. The Verizon sim is roaming on pelephone and there is no way to turn it off and force data switching… any ideas??

[yeshivabachur613]

You can turn off data roaming but not voice roaming so I can’t force backup calling…

[cgr]

For Android (for sure Samsung, maybe others too) it can't be done with phones sold in the US market. I couldn't get it to work on my S21 on a recent trip to Europe even after playing with carrier settings like you described. Something to do with US carriers disabling it so they can gouge you for a $10/day international travel plan, though you won't see anything official about this. Supposedly it works on non-US dual sim phones. US phones are missing the "backup calling" feature.

Is this true for esims as well? I was hoping to add a Google Fi esim as my secondary service, and switching off my primary while abroad.

[JudahMcB]

Is this true for esims as well? I was hoping to add a Google Fi esim as my secondary service, and switching off my primary while abroad.

Yes

[cgr]

Yes

[yelped]

Seems to work on my Pixel 7. (Not roaming now, but definitely supports 2 eSims).

[cgr]

Seems to work on my Pixel 7. (Not roaming now, but definitely supports 2 eSims).

My Android also supports two esims but from what I'm reading it doesn't actually work when roaming.

[cgr]

My Android also supports two esims but from what I'm reading it doesn't actually work when roaming.

I managed to activate two lines of service on my Verizon Samsung device. Verizon via esim and Google Fi via physical sim.

Turning off the Verizon sim will prevent it from incurring any roaming fees, but it will also send all calls to voicemail and texts won't come through, because as mentioned upthread dual sim on Verizon doesn't let one sim to act as "wifi" for the other sim.

Being that I do need my Verizon sim to be active for calls and texts, I was thinking of opting into the Verizon Pay As You Go plan- the fees are exorbitant, but I don't plan on answering calls via the Verizon line- I just need to know when they come in. Incoming texts is a bit of an issue but I might just have to put up with it (5 cents per text). Outgoing texts I can again use my other line for so that's not an issue either.

Now for the actual question: how can I keep the Verizon sim card active while disabling mobile data only for that specific sim? Is that an option?

[cozmohoot]

I managed to activate two lines of service on my Verizon Samsung device. Verizon via esim and Google Fi via physical sim.

Turning off the Verizon sim will prevent it from incurring any roaming fees, but it will also send all calls to voicemail and texts won't come through, because as mentioned upthread dual sim on Verizon doesn't let one sim to act as "wifi" for the other sim.

Being that I do need my Verizon sim to be active for calls and texts, I was thinking of opting into the Verizon Pay As You Go plan- the fees are exorbitant, but I don't plan on answering calls via the Verizon line- I just need to know when they come in. Incoming texts is a bit of an issue but I might just have to put up with it (5 cents per text). Outgoing texts I can again use my other line for so that's not an issue either.

Now for the actual question: how can I keep the Verizon sim card active while disabling mobile data only for that specific sim? Is that an option?

Can't you forward the Verizon calls before you leave?
And for sms, try out message plus by Verizon which uses data for sms...

[cgr]

Can't you forward the Verizon calls before you leave?
And for sms, try out message plus by Verizon which uses data for sms...

Will those work if the sim card is disabled? Or will calls be sent to voicemail and texts stuck in cyberspace because the sim is set to inactive? (Was also trying to prevent having a multi step to do list that I need to remember before every trip like call forwarding etc but I can live with it).

[cozmohoot]

Both should work even if Sim is taken out of phone or disabled.
U can Test both here in USA.
Try message plus first and once it's working put the phone on airplane mode with only wifi on to see if it works

[cgr]

Both should work even if Sim is taken out of phone or disabled.
U can Test both here in USA.
Try message plus first and once it's working put the phone on airplane mode with only wifi on to see if it works

Verizon is claiming that Message+ only works over wifi if both sender and recipient are using Message+...

[cozmohoot]

I haven't done it recently and now I don't use Verizon anymore. Sorry if what I wrote doesn't apply anymore...
Call forwarding should not be an issue

[cgr]

I haven't done it recently and now I don't use Verizon anymore. Sorry if what I wrote doesn't apply anymore...
Call forwarding should not be an issue

I appreciate the input! Verizon opened a ticket about this issue because even though the rep said that it only works with other Verizon Message+ senders, I'm seeing online that it's supposed to work across the board over wifi. Don't have much faith in them but let's see what happens.

[Buruch]

What about porting your number to google voice, and just using your phone plan for signal? That way anywhere you go, you just need data and everything else is seamless.

[Hamagid]

I appreciate the input! Verizon opened a ticket about this issue because even though the rep said that it only works with other Verizon Message+ senders, I'm seeing online that it's supposed to work across the board over wifi. Don't have much faith in them but let's see what happens.

I use the Verizon+ app on iPhone for a sim that’s in a flip phone, it works fine even when the flip phone is turned off.

Some security messages (2fa) does not come through, but that’s even the flip phone is on.

[cgr]

What about porting your number to google voice, and just using your phone plan for signal? That way anywhere you go, you just need data and everything else is seamless.

I need to use Verizon when I'm local.