Data roaming charges despite data roaming switched off

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Level 1

4 points

Data roaming charges despite data roaming switched off

I’m using two numbers - one physical SIM and one eSIM. My eSIM is on roaming, but I have made sure that my data roaming is switched off.

Every time I receive a a regular voice call on my roaming number, not only am I charged for the call while on roaming, I’m also charged for data roaming.

My carrier informed that the data roaming charges are related to roaming IMS (IP Multimedia Subsystem). These charges occur when my device uses certain features like Voice over LTE (VoLTE), Wi-Fi calling, or other data-based telecommunication services while in a roaming zone. To switch off VoLTE, I was asked to choose 3G under the “Voice & Data” settings, but 3G is not even an option! Hence I had to leave it on 4G

Following the advice from my carrier, I have also switched off WiFi calling.

Despite these, the data roaming charges continue to incur.

I have used this dual phone number setup - SIM (local) and eSIM (roaming) on my iPhone 12 for the past 4 years. This only seems to be happening after switching to iPhone 16

Appreciate any advice or help

iPhone 16 Plus, iOS 18

Posted on Feb 17, 2025 09:44 AM

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Answer 1

BonBonBun Author

Level 1

4 points

Feb 17, 2025 05:30 PM in response to Jeff Donald

Celcom is the network that RedONE is using I believe. Their description:

redONE Network Sdn Bhd was established in 2012. We are proudly known for being the first Mobile Virtual Network Operator (MVNO) to provide mobile Postpaid services by using Celcom Axiata's fast and reliable 5-star network infrastructure.

My main SIM (Singtel) has data turned on all the time. I’m also very frequently connected to WiFi. If apps want to use data, why would they use my roaming line? To be clear, following are my settings:

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Answer 2

Jeff Donald

Level 8

41,424 points

Feb 17, 2025 10:17 AM in response to BonBonBun

Who is Celcom? It looks the iPhone did some instant messaging. Are you using any messaging apps like WhatsApp, Facebook Messenger, Telegram etc.? There literally are dozens and dozens of IM apps. I wonder if you’re getting billed when the apps update while you’re roaming? Many messaging apps push data to the apps and then the apps try to connect if a connection is available.

You’ll have to turn off each app for cellular data.

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Answer 3

BonBonBun Author

Level 1

4 points

Feb 18, 2025 08:05 AM in response to Jeff Donald

I switched off cellular data for the Facebook Messenger app. Do you know of any way I could test whether it indeed was the Messenger app?

I have few questions:

1) How is the Messenger app able to send data when my data roaming is off?

2) Why doesn’t it use my Singtel data or WiFi instead?

3) Do you know why it only seems to coincide with the times that I’m answering calls when on roaming?

My apologies for having so many questions. I really need to get to the bottom of this. Paying data roaming is really expensive.

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Answer 4

Jeff Donald

Level 8

41,424 points

Feb 18, 2025 08:27 AM in response to BonBonBun

1) The Messenger app may or may not be the culprit. It was meant as an example to illustrate the issue you’re confronting.

2) Again, just illustrating a point. Specifics will come from the cellular services. They could tell you the IP address of the place the data was sent. They won’t disclose that. So you’re left with nothing other than trial and error in figuring out what app(s) are responsible for the charges.

3) Only the data service provider is able to tell you where the data went or where it came from.

I’ve solved my issue by not using any IM service but Apple Messages when I travel/roam. I disable Messenger and all other messaging apps.

Have you tried contacting the carrier that billed you? If you didn’t use data, make them prove it to you.

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