Don't Pay For Roaming Charges! How to Use Cellular Backup Calling

[@travisd05]

Thanks for this video. Exactly what I needed. Almost eerily close to what I need. I'm using Tello on an iPhone 12 mini too. One question: My secondary line that I'm using for data is Google Fi, which does have voice and text capabilities too. When I just tried this, even though Tello was set as my primary voice option, it switched to Google Fi when making the call. I tried it again and had to select "Always use Tello with this contact" in order for the call to go through Tello. Is there a way to do that for all calls? Make it so that it always uses Tello over Google Fi data instead of automatically switching to Google Fi for calls?

[@TechThatDoesntByte]

Hi travisd05. Thank you for the comment. Unfortunately at the moment we can't bulk edit our contacts list to set the preferred line for calls. It's most likely an iOS limitation that hopefully will be addressed in future updates. But for now we have to manually select the preferred line for each individual contacts.

[@travisd05]

@@TechThatDoesntByte Ok. Thanks for the reply!

[@TechThatDoesntByte]

Additional information - Make sure that you have enough minutes & text on your primary line. If your primary carrier has roaming capabilities you might be able to disable roaming before you travel, so check with your carrier first.

[@starleo30]

Can we do this for esim.?

[@game-fk3ru]

Cool video but will it work with data on a standard SIM instead of esim?

[@TechThatDoesntByte]

Hi game-fk3ru. Thanks for the comment! It should work the same with dual physical sim cards as well. Apple has a support article that indicates that this feature works with iPhones that are sold with dual physical sim cards. The iphone I use to test is using 1 physical sim card + 1 esim. support.apple.com/en-us/HT209086

[@almostbreathing]

older non-techie here. I'm so confused! I have the inverse situation? I have Claro with vowifi (no roaming) as primary and US Tello (no roaming) as secondary. Tello supposedly has vowifi but I can't get it to work. Tried every combination and still can't receive or make calls. Could you make another video perhaps?

[@farisnajjar1466]

Does the "cellular backup calling" work on all iPhone versions, i.e., US and international versions?

[@TechThatDoesntByte]

Hi. Thanks for the comment! It should work with iPhone's from the US and international version. The requirement is an iPhone with iOS 13 or later with dual sim capabilities. support.apple.com/en-us/108898

[@emintahirsobucovali7253]

First of all, thank you for the nice explanation. I am using Xiaomi Mi10 (umi). With Vowifi on my phone, I can talk and receive messages abroad over wifi. However, I cannot make backup calling via data sim. Is there any way to solve this?

[@TechThatDoesntByte]

Thank you for the comment! This feature might or might not exist depending on the brand of your phone. I think it's up to the phone manufactuer if they want to support this feature. I believe that newer Pixel and Samsung phones have this feature but I'm not sure about other brands. In this case you'll need to find other Xiaomi users and see if they have this feature. XDA forums is a good place with a lot of Android users.

[@andrewrandle3228]

If you went with a more premium cell provider that allowed mms would that then be possible over the cellular data or is there no work around for that?

[@TechThatDoesntByte]

Hi! Thanks for the comment. It's really a hit or miss when it comes to MMS. Some users of those premium cell provider are able to send MMS via wifi-calling and some aren't able to. I did a search on google using this question "can you send mms over wifi calling (enter the carrier name)?" It's a mix result.

[@karthiknbv7251]

can you do a video for android aswell please?

[@online9191]

Do you still have the feature after you update it to android 14? I heard it’s removed from android 14

[@TechThatDoesntByte]

Hi. Thanks for the comment! At the moment I don't have an Android that supported this first feature. My Android phone never supported the feature to begin with. However, I had a family member that was using the Pixel 6 and had this feature but now that person recently switched to a Z Flip5. I'm not sure if the backup calling is on the Z Flip 5. I did some research on Android 14 and it does appear that the backup calling feature has been removed on Pixel devices after you upgrade to Android 14.

[@slavomirzaborsky620]

Hi,SAMSUNG Galaxy S still have this feature after update to Android 14. if the second SIM card is in roaming mode on Android, this function does not work (the case of so-called travel eSIM cards)

[@sachindaftari]

It doenot work in india