Can you make VoWiFi calls when roaming in another country using either WiFi or an eSIM?

Forums › Mobile handsets › Can you make VoWiFi calls when roaming in another country using either WiFi or an eSIM?

lchiu7

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#318056 11-Dec-2024 08:17

I plan to be travelling soon and my current phone (Pixel 8) and carrier (Kogan via ONZ) supportw VoWiFi. If I am in the foreign country and have an eSIM for data or use a WiFI network, should I be able to make calls from my usual number? The phone is connected to the Internet so I presume it should not make any difference what the Internet connection is? If that works that would be really useful.

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#3319035 11-Dec-2024 08:29

Yes unless you are SparkNZ customer!

I have used 2degrees Wi-Fi calling around the world (handset into flight mode) enable Wi-Fi and away you go :)

Asteros

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#3319037 11-Dec-2024 08:34

I see you're on Android. To add to this point, I have read that the Galaxy S models allow mobile data switching between SIMs so you can use a foreign SIM card and Kogan voWifi will continue to work. I assume Pixels will allow this as well. Personally I have gotten this to work on ios 18 on an Iphone 15 Pro Max recently in Asia.

lchiu7

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#3319049 11-Dec-2024 08:55

Cool. That is great. Does that also mean I can receive incoming calls?

[EDIT]. Just put the phone into flight mode. Turned on Wi-Fi and was able to make a call on my own network. That's pretty cool. Out of interest why cant you do this on Spark?

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#3319060 11-Dec-2024 09:12

That is the idea of Wi-Fi calling handset works the same as if the handset is attached to a physical cellsite

nztim

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#3319066 11-Dec-2024 09:17

@cokemaster posted about this and it works on iPhones..... whereby the phone can use mobile data of another sim to do wifi calling

The trick is to get ONE NZ to permanently disable the ability for the sim to connect to a foreign carrier doing this with a Kogan Sim might be tricky as while it is just resold One NZ you don't have access to the resources and 2nd tier support.

The simplest way to do this is get a 4G Wifi Hotspot in the country you are visiting instead of another SIM and disable mobile networks on your phone

The downside of this is you have to carry two devices

I cannot for the life of me find the thread where this was discussed

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lchiu7

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#3319078 11-Dec-2024 10:06

nztim:

@cokemaster posted about this and it works on iPhones..... whereby the phone can use mobile data of another sim to do wifi calling

The trick is to get ONE NZ to permanently disable the ability for the sim to connect to a foreign carrier doing this with a Kogan Sim might be tricky as while it is just resold One NZ you don't have access to the resources and 2nd tier support.

The simplest way to do this is get a 4G Wifi Hotspot in the country you are visiting instead of another SIM and disable mobile networks on your phone

The downside of this is you have to carry two devices

I cannot for the life of me find the thread where this was discussed

As I noted earlier when I put the phone into Flight Mode and then enabled WiFi I was able to make calls using VoWiFi

I have a couple of eSIMS that I purchased and loaded onto my phone so what I will do is, when I arrive in the country and it tries to connect to the Kogan SIM, if I can't disable it, I will just remove it. But that might mean while I can possibly still make calls I might now not be able to receive inbound SMS which I know I can do, even if I am not roaming.

Flight Mode won't work with the eSIM since putting the phone into Flight Mode will disable that also.

Another option is to take another phone and put my Kogan SIM in it and have it just to receive incoming SMS. Don't mind carrying two phones if I can make calls justing a data only eSIM.

Staying in Wellington. Check out my AirBnB in the Wellington CBD. https://www.airbnb.co.nz/h/wellycbd PM me and mention GZ to get a 15% discount and no AirBnB charges.

CYaBro

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#3319080 11-Dec-2024 10:09

If you remove the Kogan SIM then wifi calling won't work either, for your Kogan number.

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nztim

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#3319085 11-Dec-2024 10:19

lchiu7:

so what I will do is, when I arrive in the country and it tries to connect to the Kogan SIM, if I can't disable it, I will just remove it. But that might mean while I can possibly still make calls I might now not be able to receive inbound SMS which I know I can do, even if I am not roaming.

This wont work, if you remove the Kogan Sim you will not be able to make/recieve calls on the Kogan number

At network level it needs to be barred from connecting to a foreign network, or if you phone supports it just enable flight mode for just the kogan sim

Failing that, you will need an e-Sim/sim in a mobile hotspot that your phone will connect to and use wifi calling

Any views expressed on these forums are my own and don't necessarily reflect those of my employer.

lchiu7

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#3319088 11-Dec-2024 10:45

nztim:

lchiu7:

so what I will do is, when I arrive in the country and it tries to connect to the Kogan SIM, if I can't disable it, I will just remove it. But that might mean while I can possibly still make calls I might now not be able to receive inbound SMS which I know I can do, even if I am not roaming.

This wont work, if you remove the Kogan Sim you will not be able to make/recieve calls on the Kogan number

At network level it needs to be barred from connecting to a foreign network, or if you phone supports it just enable flight mode for just the kogan sim

Failing that, you will need an e-Sim/sim in a mobile hotspot that your phone will connect to and use wifi calling

OK thanks for that information. If I don't have roaming enabled, will the phone try to connect to a foreign network?

[UPDATE]

I asked Gemini and iot looks like I can disable the SIM and I presume then calls revert to VoWiFi (which I didn't ask Gemini)

The Pixel 8 and Pixel 8 Pro both support Dual SIM Dual Standby (DSDS) technology. This means that both your physical SIM and eSIM can be active simultaneously, but only one can be used for data at a time.

Here's how to use Flight Mode with one SIM active on your Pixel 8:

Enable Flight Mode: Swipe down from the top of the screen to open the quick settings menu. Tap the airplane icon to turn on Flight Mode. This will disable both SIMs.
Reactivate Your eSIM (or physical SIM):
- Go to Settings > Network & internet > SIMs.
- Tap on the SIM you want to keep active (eSIM or physical SIM).
- Toggle the "Turn on this SIM" option to ON.

Now, your chosen SIM will be active even though your phone is in Flight Mode. The other SIM will remain disabled.

Important Notes:

Data Connection: Remember that only one SIM can use mobile data at a time, even outside of Flight Mode. You can choose which SIM is preferred for mobile data in the SIM settings.
Calls and Texts: If you have a call or text come in on the disabled SIM while in Flight Mode, you won't receive it.
Wi-Fi and Bluetooth: Flight Mode also disables Wi-Fi and Bluetooth. 1 You can re-enable them individually in the quick settings menu if needed.

1. Keep your Android's wireless connections on in Airplane mode - Pixel Phone Help

support.google.com

This feature is handy for situations like:

International Travel: Keep your eSIM active for local data while disabling your home SIM to avoid roaming charges.
Separating Work and Personal: Use your physical SIM for work and your eSIM for personal use, and easily switch between them.
Battery Saving: Disabling one SIM can help conserve battery life if you don't need both active.

Staying in Wellington. Check out my AirBnB in the Wellington CBD. https://www.airbnb.co.nz/h/wellycbd PM me and mention GZ to get a 15% discount and no AirBnB charges.

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#3319089 11-Dec-2024 10:49

Disabling data roaming and actual roaming is very different so please clarify what is getting disabled?

It would not be possible for a handset to connect to a foreign network if ' roaming ' is disabled on the service providers side

lucky015

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#3319090 11-Dec-2024 10:49

lchiu7:

Cool. That is great. Does that also mean I can receive incoming calls?

[EDIT]. Just put the phone into flight mode. Turned on Wi-Fi and was able to make a call on my own network. That's pretty cool. Out of interest why cant you do this on Spark?

I'm sure Spark make some excuse about technical capability/effectiveness but it's entirely so they can screw you on roaming charges, I've heard of it working in AU which I'm not sure if it's intentional or accidental.

Also worth noting Spark looked to be by far the most restrictive on handset support on release of Wifi Calling in an obvious attempt to force users to have to buy handsets from them which since appears to have been a bit relaxed.

nztim

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#3319091 11-Dec-2024 10:51

lchiu7:

OK thanks for that information. If I don't have roaming enabled, will the phone try to connect to a foreign network?

yes, for emergency calls, you have to put a specific request into OneNZ to stop the Sim connecting to a foreign network

If you have another phone, you can put the e-sim on, Ane use it as a wifi hotspot that will solve all your issues

Then keep your Kogan/ONE phone in flight mode

it just means carrying two devices

Any views expressed on these forums are my own and don't necessarily reflect those of my employer.

lchiu7

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#3319273 11-Dec-2024 13:33

nztim:

lchiu7:

OK thanks for that information. If I don't have roaming enabled, will the phone try to connect to a foreign network?

yes, for emergency calls, you have to put a specific request into OneNZ to stop the Sim connecting to a foreign network

If you have another phone, you can put the e-sim on, Ane use it as a wifi hotspot that will solve all your issues

Then keep your Kogan/ONE phone in flight mode

it just means carrying two devices

I am going take two phones but if the Google instructions for disabling a SIM works, then I can leave one phone in the hotel room :-)

Staying in Wellington. Check out my AirBnB in the Wellington CBD. https://www.airbnb.co.nz/h/wellycbd PM me and mention GZ to get a 15% discount and no AirBnB charges.

Asteros

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#3319438 12-Dec-2024 07:27

Disclaimer: I only have iPhones running iOS 18 so am translating equivalent settings to Android. I got it to successfully run One wifi calling on a Nomad esim in Asia on iOS 18. I asked a friend with a Pixel 8 and these settings exist but haven’t been tested overseas on roaming

Ensure you have turned on Kogan wifi calling in NZ before leaving.

In NZ do the following:

Settings: network and internet - select Kogan sim

Unselect: Automatically select networks

Choose network: select Kogan Nz

The phone will look for only Kogan NZ and won’t connect to a foreign network so no roaming charges and you don’t need to block roaming at the Kogan network level.

After you have purchased and installed a foreign sim/esim:

Settings - network & internet - sims

Turn on: Automatic Data Switching

These settings should allow you to receive calls and sms on your Kogan number via wifi calling but your data is provided by the foreign sim/esim.

lchiu7

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#3322250 19-Dec-2024 11:29

I got it working but it took a bit fiddling. I have both the kogan an eSIM active in the phone like this

But then in the Kogan SIM I selected do not connect to data services when roaming so it will never try to connecct to data.

Data is turned on for the eSIM and now when I make a call jusing NZ dialling format, it calls fine. And I can send SMS also.

Staying in Wellington. Check out my AirBnB in the Wellington CBD. https://www.airbnb.co.nz/h/wellycbd PM me and mention GZ to get a 15% discount and no AirBnB charges.

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