Sudden Increase in data consumption

why has my Iphone 16 started using gigabytes of date each day instead of kb or mb, It started 28th January 26 and has consumed 9 months of data since

iPhone 16, iOS 26

Posted on Feb 8, 2026 9:01 PM

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Question marked as Top-ranking reply

Posted on Feb 13, 2026 2:31 AM

Wombatalso wrote:

Thank you - I found the culprit.
Apparently at the last iOS update iCould Sync was turned on for all apps, and the main drain was syncing Contacts every day (4.92Gb on one day). Thanks Apple!! I have a 12 month phone plan that has 50Gb date which usually lasts just on the 12 months - this little episode consumed 9 months of date in a month and a half. Not happy!!!

How many billion contacts do you have?

9 replies
Question marked as Top-ranking reply

Feb 13, 2026 2:31 AM in response to Wombatalso

Wombatalso wrote:

Thank you - I found the culprit.
Apparently at the last iOS update iCould Sync was turned on for all apps, and the main drain was syncing Contacts every day (4.92Gb on one day). Thanks Apple!! I have a 12 month phone plan that has 50Gb date which usually lasts just on the 12 months - this little episode consumed 9 months of date in a month and a half. Not happy!!!

How many billion contacts do you have?

Feb 12, 2026 9:56 PM in response to Wombatalso

Thank you - I found the culprit.

Apparently at the last iOS update iCould Sync was turned on for all apps, and the main drain was syncing Contacts every day (4.92Gb on one day). Thanks Apple!! I have a 12 month phone plan that has 50Gb date which usually lasts just on the 12 months - this little episode consumed 9 months of date in a month and a half. Not happy!!!

Feb 13, 2026 8:03 PM in response to Wombatalso

I don't have a lot of contacts so obviously something else has happening - I read somewhere that iCloud Sync also will backup the entire phone -Apps and data. what ever it was doing it was going through Gigabytes of data every day.

I turned of sync for all apps and only left calendar active as my wife and I share calendar appointments. I also turned off anything that involved battery usage as that was being discharged by lunchtime, Everything is now running smoothly and no more surprises (touch wood)

Feb 9, 2026 12:44 AM in response to Wombatalso

You may --> Check the cellular data usage on your iPhone and iPad ...


Worried about data consumption?

  1. Disable Push notifications for apps you do not use often --> Use notifications on your iPhone, iPad, and iPod touch - Apple ...
  2. Location services to be allowed only while using the app --> Turn Location Services and GPS on or off on your iPhone, iPad
  3. Set your iPhone to fetch email and calendar data from internet less frequently --> Push Fetch email Settings - Apple Community
  4. Turning off Background App Refresh --> Switch apps on your iPhone, iPad, or iPod touch - Apple Support
  5. Disable auto backup for any third party apps (e.g. WhatsApp) --How to back up to iCloud - WhatsApp FAQ
  6. Uneasy about automatic App updates? Turn on or turn off automatic updates. 
  7. Disable WiFi Assist --> About Wi-Fi Assist - Apple Support


Feb 13, 2026 8:21 PM in response to Wombatalso

"Sudden Increase in data consumption: why has my Iphone 16 started using gigabytes of date each day instead of kb or mb, It started 28th January 26 and has consumed 9 months of data since"

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Cellular Data Beng Eaten Up:

Turn Off Cellular, when you don't need it. If that doesn't make the fix, then I'd contact your Cellular Carrier, and tell them what is occurring here. You might be streaming iTunes items in loops, or downloading all of iCloud Drive items.

Sudden Increase in data consumption

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