iPhone X EXCESSIVE data usage

Thanks for setting the scene better. In general the figures in cellular data should be accurate. I'm going to go out on a limb here, and propose a way they may not be - retransmission when a connection is weak. Based on my knowledge of digital communications (which is pretty extensive). An app sends data, or receives data. If everything works, I send 1000 bytes, the the communications channel adds some overhead and sends 1000 bytes. The overhead includes integrity checks ('checksums", but not really) that verify that the transmission was received correctly. If the checks fail the packet is re-sent, and repeated until it is received correctly. It's possible, even likely, that the function in iOS that records the data used by the app only knows about the 1000 bytes, not the retransmissions. But the carrier still records the retransmissions as data (remember that the carrier doesn't know anything about the contents of the packets). So my 1000 bytes will be displayed in Settings/Cellular as 1000 bytes, but if it was retransmitted twice the carrier will "charge" for 3000 bytes. This is just speculation, but it could explain why the data usage reported by the carrier (and charged for) is higher than what the phone displays.

Regarding Wi-Fi, if Voice over Wi-Fi is enabled the carrier actually records that Wi-Fi usage and reports it on your bill as usage. It's one reason that most carriers have gone to unlimited talk (the other is that more people text than talk these days). However, If I call a friend in Paris from New York I get charged for an International call, even though it went over Wi-Fi. Not hypothetical; I DO call friends in Paris from NY and see the charges on my bill.

However, backups do not use cellular data - ever. Voicemail does; it can't use Wi-Fi. Likewise for some notifications and for MMS. Anything that goes through the carrier must use cellular data, because the carrier's system doesn't know how to address your Wi-Fi channel.

Is there a special reason why you have set:

Settings > Cellular > Cellular Data Options = "Roaming On"?

I have used iPhones for many years, and have never done that anywhere within the U.S. I suggest turning it to "Roaming Off" - unless you happen to travel internationally frequently and are fully aware of the consequences of your action.

https://support.apple.com/en-us/HT201643

Yes, please report back how you did with cellular use during your trip.

Here's one other thought - from the "Get Help" section of this article:

Check the cellular data usage on your iPhone and iPad - Apple Support

Do you happen to be using an Exchange ActiveSync account? If so, that might explain ...

What you should do is go to Settings/cellular (it may be called something different in your language) and see which apps and system services are using data. As a check on retransmission, at the start of your next billing period go to Settings/cellular, scroll to the bottom an tap Reset Statistics. After you have done this the total data usage reported on the phone should match the usage reported by your service provider (approximately). There will be a small difference due to overhead.

If if there is a large discrepancy call your provider and complain And follow the advice from Philly_Phan.

Eric,

Here’s one of the discussion pages regarding this cell data issue in case you want to get up to speed on this.

https://discussions.apple.com/thread/8191005?answerId=32685518022#32685518022

Richard C.

Mobile: ***

Home: ***

Sent from mobile device.

According to your bottom screenshot, you have cellular turned ON not off. Turn cellular off and that should solve your issue.

I find that very interesting... the issues you had with your phone are basically identical to the issues I have been having. When I got the phone I tried to restore my backup from iCloud but the backup was corrupted as well. Once I finally restored the backup to my phone is when I experienced the issues. There must be some kind of bug in the software. I sent some logs to apple this evening so they can track where exactly the data is being used from. Hopefully that helps me.

I have a supervisor at Apple looking at this. I’ll let you know what we discover. At this point, he had me turn off cell data. Wednesday he’ll call back to analyze any cell data use. Shouldn’t be any. He hadn’t heard of the issue. AT&T said to call Apple. They had no idea why this sudden change to heavy cell data use with the iPhone X if switches were off and WiFi environment stable. They both mentioned that with the new X screen resolution cell data is going to increase substantially, so be careful if you are out, away from WiFi, and your cell data plan is limited.

I know you are not saying battery but if you go to the battery settings you can see what is using the phone.

Is your wifi data limited or your cellular? you need to use wifi to prevent data from being used up. My wifi is connected to my internet service provider so there is no limit. cellular is 6gb limit for data.