Why is System Services consuming excessive data on iPhone 15 Pro Max?

I can reproduce the error quite reliably, even after resetting the phone, and in my case comes down to a number of steps I do day-to-day.

1. I don't sync photos (3k+) with iCloud, Apple Intelligence on (and has finished whatever it needs to do)
2. I turn on Personal Hotspot (via Control Center) because I'm driving somewhere and VW's CarNet needs to piggyback off a hotspot.
3. I turn off Personal Hotspot (via Control Center)
4. I use the Apple camera app to take a picture
5. Lots of data suddenly starts getting consumed
6. Now repeat steps 2-4 but with Apple Intelligence turned off, no consumption of data after taking a photo.

The odd thing here is I always had Apple Intelligence turned on, but, I more recently changed how how I turn the personal hotspot on and off. Previously via Settings/Personal Hotspot/Allow Other to Join.

However I've noticed there's a bug in toggling Personal Hotspot on/off using the Control Center, press it once, it turns on OK, press it again, claims it is off, BUT, it isn't. If you look in Settings/Personal Hotspot "Allow Other to Join" is still enabled. So does this mean Apple Intelligence is slurping data if wifi is available and bizarrely personal hotspot turned on?

BTW, workaround for the Personal Hotspot toggling in Control Center would be to create two Shortcuts, one to turn on and the other to turn off and add those to the Control Center.

Hi All,

After a few weeks of trying the “Apple intelligence off”, personal hotspot and cellular data management fixes; I realised the issue persisted. The only remaining culprit was Siri, which I have switched off the option for iPhone to listen for Siri.

I will monitor and advise further.

A reset without a back up will be going backwards instead of ripping the long years with Apple.

I have an iPhone 15 Pro unlocked refurb purchased direct from Apple and activated in May 2025 with iOS 18.x.

I always toggle Cellular Data off and use only WiFi for iOS and app updates. I'm on a low-cost prepaid cellular plan, so I keep close track of cellular data used, and turn data off for most apps, except Mail, Calendar, Contacts, Notes, Camera, Phone, Photos, and Find My.

My prior phone (iPhone 12 Pro) was not Apple Intelligence capable. My typical Cellular data usage with that phone was 150Mb -250Mb per month. Siri is activated only with a button-press.

Immediately after using the built-in migration tools to transfer apps and data and activate the iPhone 15 Pro, I saw large amounts (250Mb-500Mb) of cellular data being used within hours when both Apple Intelligence and Cellular data were toggled on, even while at home, and connected continuously to WiFi. In two months, I'd used over 4GB of System Services General cellular data, far more than ever before.

So I suspect that Apple Intelligence was/is using large amounts of Cellular > System Services > General data.

There is no separate category for Apple Intelligence currently listed under the detailed System Services cellular data.

Since I've toggled both Apple Intelligence and Cellular data off, except for the apps noted above, my typical cellular data use is back to single-digit Mbs in a day, more when I use Apple Maps for navigation with wireless CarPlay on my 2025 Ford.

Following the IOS 18.6 update, the breakdown of the system services usage of mobile data is more granular and the culprit is software updates.

Therefore, my next trial is to keep App Store connected only via WIFI for the next few weeks.

I already lost 1.13 Gb data on the first day of August; so I have a good benchmark.

[Edited by Moderator]

1. Is this your corporate/organisation/enterprise/School Management iPhone? Then please contact the system administrator of your corporate//organisation/enterprise/School Management
2. If it is your device, in that case, do you have any profile installed by your corporate/organisation/enterprise/School Management?
   1. Erase the profile added by you If you have installed a profile on your own --> Install or remove configuration profiles on iPhone - Apple ...
   2. Or please contact the system administrator of the organisation who provided the profile to you

A corporate profile installed on your iPhone could potentially be contributing to the inaccessibility of certain features. 

Here's why:

• Restrictions: Corporate profiles can have restrictions placed on apps and functionalities. These restrictions might be limiting some activity, causing it to be unresponsive or quit.
• Managed Apps: IT departments might deploy specific navigation apps through the profile, potentially blocking certain functions or features.
• Security Settings: Corporate profiles often have stricter security settings that could affect app or function behavior. This might be causing unexpected behavior of an App or functions.

Here's what you can do:

• Check with IT: The best course of action is to contact your IT department. They can explain the restrictions set by the corporate profile and see what is affected. They might be able to adjust settings or suggest alternative apps or features approved for corporate use.
• Look for App Conflicts: See if your IT department uses a different app through the corporate profile. Conflicting apps might cause crashes.

Additional points to consider:

• Even if the profile isn't directly affecting the function, it's still a good idea to check with IT. They might be aware of similar issues and have workarounds.
• While troubleshooting, make sure you prioritize safety. Don't fiddle with your phone. 

By working with IT and considering these possibilities, you can hopefully identify if the corporate profile is the culprit and find a solution that allows you to use the iPhone to your liking.

To see how much mobile data you've used, go to Settings > Mobile. If you're using an iPad, you may see Settings > Mobile Data. If your device is enrolled in Mobile Device Management, related data will be reported in System Services > Corporate Accounts. Scroll down to find out which apps are using mobile data.

Use mobile data on your iPhone or iPad - Apple Support (IN)

I've been seeing similar behaviour over the last 4 weeks, excessive System Services, General mobile data usage. Not related to corporate profiles. I only need to step out of the house and no longer be on Wifi and the phone will happily chew through about 1Gb/hr until I've exceeded my monthly contract limit.

What is covered by the System Services, General? Apps otherwise consume the small amount as typically expected.

I'm curious to know which cellular company you people use. Is it Verizon by any chance?

The reason I ask is that my problem with the excess mobile data consumption for "System Services > General" began after I switched from ATT to Verizon. Maybe it's just a coincidence.

I am thinking of solving the same data usage problem my iPhone 15 Pro the way you did - reset the phone and not restore from backup. It's been 12 days since your post, so I just want to confirm that the problem is definitely gone on your phone before I reset my phone.

Thanks