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Excessive mobile data (cellular data) usage by Documents & Sync

I've had a problem for the last 3 or 4 days of my iPhone using excessive amounts of mobile data.


Typically in an entire month I use about 3GB of data. In the last 4 days I've used over 2GB despite spending most of the time in locations with WiFi.


Once I realised something was up (when I had to buy 2x 1GB data upgrades within 72hrs). I started looking for a cause using the data given under Settings > Mobile Data (Cellular Data).



Tried a couple things:


1). Under Settings > iTunes & App Stores "use mobile data" was set to On.


This was odd, I'm pretty certain last time I checked this was set to off. Anyway, I changed it back to off.


Under Mobile Data > System Services I could see the data used by iTunes had dropped back. This helped reduce data usage but hasn't solved the problem.


2). Under Settings > iCloud > iCloud Drive "use mobile data" was set to On.


Didn't know about this one, but discovered it googling for a solution. I changed it to off. Made very little difference.

After making these changes I switched Mobile Data back on. I was still seeing massive data usage, about 50MB in 30 minutes.

When I checked back in Mobile Data > System Services by far the biggest user of data is listed as "Documents & Sync". I don't know what this does.

I signed-out of my iCloud on the phone. This did seam to help but I couldn't leave things this way for long as I was missing my calendar and contacts so I signed back in and switched on all my iCloud services (except email) again.

So right now I have mobile data switched off completely. I'm only able to use my phone on WiFi, so it's basically a super expensive iPod Touch.

I really need some help with this, I'm hoping somebody can please point me at a solution or at least explain what might be using data labeled as "Documents & Sync".


If I can't get to the bottom of this one I'll have to switch to another phone, my carrier here in New Zealand don't offer unlimited plans :-(


Some details on my phone and settings:


  • iPhone 6 running iOS 9.2.1 (13D20)
  • Phone has 128GB storage with about 10GB free space
  • iCloud I use for everything except email and document storage
  • I have iTunes Match and Apple Music subscriptions
  • iCloud Photo Library is switched on
  • Everything I can find with a setting for it except for Apple Music is set to only use data over WiFi

iPhone 6, iOS 9.2.1, 128GB

Posted on Mar 16, 2016 2:37 AM

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Feb 11, 2017 4:25 AM in response to bryan.vance

Dude that would be 5.4gb a day. I am experiencing a whopping 120 to 150 a month gb usage. Even with WiFi on a data off. Yet when you look on the phones stats and add everything up it isn't even close. What I am thinking is everything an iPhone does is converted into a data stream for security,phone calls texts, everything. So basically if you have an iPhone on and not connected to WiFi and actually use it you are using data. That is one expensive *** clock.

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May 9, 2017 5:45 AM in response to russelljsmith

I have had this problem recently as well, iPhone 6, iOS 10.3.1, and I think I am on to something. A couple of months ago I had this issue where, out of the blue my Documents & Sync usage was up by 600MB in a couple of hours, very unusual, I searched and searched to see where I could turn off or limit its usage and followed all suggestions but the only effective thing was to turn off mobile data completely. Not good.


Photos, iCloud Drive, Wi-Fi assist and iTunes & App Store mobile usage are all turned off, which didn't solve the issue. Eventually, it stopped happening, and today it happened again, 400MB in less than an hour.


Now, there is one thing that happened on both occasions that I can think of that didn't happen in the time between: using my iPad and the accessory to download photos from my camera, I added a lot RAW of big photos to my iCloud Photo Library. I am wondering that, even though the Photos app is not allowed to use 4G mobile data and iCloud Drive is also not allowed to use mobile data, that the thumbnails and maybe even the optimised photos themselves are being transferred over 4G and I cannot find any options that would turn that off.


Does anybody know how I can stop the iCloud Photo Library from syncing over 4G, and has anybody experienced the same with this issue?


Thanks!

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May 9, 2017 6:55 AM in response to Csound1

Csound1 wrote:


If you want to stop Photo syncing turn it off.


I don't want to stop photo syncing, I want to occasionally stop it using my 4G connection like I can for most things (i.e. app updates) and let it continue on wi-fi only. The only way to turn off photo sync seems to be to stop using the iCloud Photo Library, which is undesirable. But thanks for the suggestion.


Also, it is only a suspicion that photos is what this is, I could not find anywhere saying that iCloud Photo Library data usage would fall under the "Documents & Sync" usage.

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May 9, 2017 6:57 AM in response to Csound1

Csound1 wrote:


It is either on or off, there is no finer control available.


Thanks, as I thought. Since there is a finer control for other things and I have found many other people with the same concern it doesn't seem unreasonable to request that there would be a finer control for this? Is there anywhere that we can request future features to Apple?


Thanks again.

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Jul 25, 2017 8:47 AM in response to russelljsmith

I have the same issue and it's incredibly frustrating cause you can make a few tweaks and it seems to go away and then one day a week all of the sudden I'll have 400 MB of "System Services > Documents and Sync" mobile data used on my phone, even when I've been on WiFi for the last 24 hours.


Apple: something is using cellular data that shouldn't be, even when the phone is on WiFi.


There are dozens of threads on these forums about it with hundreds of people clicking the, "I have this question too" button on each of the separate threads.


After reading these threads for weeks now it's apparent: there is no fix that works for everyone.


Here's an easy solution: stop letting any app put its cellular data reporting under "System Services > Documents and Sync" and force cellular data to be reported through the individual app read out (that is the entire intent of the Cellular Data settings page).

You are the richest company in the world. Fix this.

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Mar 16, 2016 5:52 PM in response to russelljsmith

An update.


It was suggested I turn off Wi-Fi assist to see if this would help.


I've run several tests. This has not apparently made any difference.


Testing in 15 minute periods I sometimes see very low data usage with WiFi assist on & I'm still still seeing very high usage at times with 4G data on and WiFi assist off.


In the worst test when I was walking with WiFi and 4G data on but WiFi assist off I saw data usage of 39.5MB in 15 minutes, of this 35.1MB was allocated back the mysterious "Data & Sync".


Test details:


Test 1.

10:00 to 10:15 local time.

  • WiFi off
  • 4G Mobile Data on and connected with good signal
  • WiFi assist off
  • Change from airplane mode at start of test
  • Stationary location during test

Total mobile data usage 1.4MB

(Documents & Sync 3.2KB)


Test 2.

10:30 to 10:45 local time.

  • WiFi on and connected with good signal
  • 4G Mobile Data on and connected with good signal
  • WiFi assist on
  • Change from airplane mode at start of test
  • Stationary location during test

Total mobile data usage 57.8KB

(Documents & Sync 2.1KB)

Test 3.

13:00 to 13:15 local time.

  • WiFi off
  • 4G Mobile Data on and connected with good signal
  • WiFi assist off
  • Change from airplane mode at start of test
  • Stationary location during test

Total mobile data usage 9.0MB

(Documents & Sync 28.6KB)

Test 4.

13:20 to 13:35 local time.

  • WiFi on but not connected to a steady signal
  • 4G Mobile Data on and connected with good signal
  • WiFi assist off
  • Change from airplane mode at start of test
  • Mobile location (walking) during test

Total mobile data usage 39.5MB

(Documents & Sync 35.1MB!!!)

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Mar 30, 2016 9:05 PM in response to russelljsmith

Hi,


I'm back. My problem is still not resolved.


What I've tried since my last post:


1). I restored my iPhone and set it up as a new device.


  • I did not connect it to my iCloud account.
  • I turned WiFi assist off.
  • I installed a few basic apps such as Facebook & Twitter from the App Store.


What happened?


Not much.


  • The phone worked fine (though I was missing all my data and most of my apps).
  • Mobile data was usage was low in general and very low for "System Services".
  • "Documents & Sync did not show up at all"


Screenshot (under a days usage):

User uploaded file



2). I signed into my iCloud account.

This activated the following iCloud features:

  • Contacts
  • Calendar
  • Photo library
  • Cloud drive
  • Keychain
  • Wallet
  • Reminders
  • Notes
  • Safari
  • Find my iPhone


I set every setting I could find to NOT use Mobile Data, WiFi assist is still off.


What happened?


Not much.


  • The phone still worked fine (though I was still missing a lot my data and most of my apps).
  • Mobile data was usage was low in general and very low for "System Services".
  • "Documents & Sync only used 4.8MB in about 5 days"


Screenshot (about 5 days usage):

User uploaded fileUser uploaded file



Both the above steps were temporary to try and find out it it was a hardware problem or an iCloud problem, next could the real test...


3). I restored my iPhone from an old back-up (one made previous to step 1 above).

Now I had all my Apps back and most of my data except for a missing 5 days. Yay!


I still have WiFi assist off, iCloud drive set to not use Mobile Data.


What happened?


"DOCUMENTS & SYNC" started using crazy amounts of data again!!!


61.5MB in about 30 minutes!!


Urgh, back where I started.


Screenshot (about 30 minutes data usage):

User uploaded file




What do I know now:


1). I'm 99% certain this is not related to WiFi assist.

2). The problem is not related to my iCloud account in general (but it could still be some iCloud data on my device).

3). I still have no idea what data is logged as "Documents & Sync".

4). I'm back to using my phone with Mobile Data off and still can't afford to have mobile data switched on.


What can I guess?


Maybe some data is corrupt on my phone and stuck in a sync loop, but I don't know what?


I'm wondering if there is a bug and something is ignoring the setting to NOT use mobile data, but I don't know how to test for that?


I could restore my phone as a new device again, but a). this is a pain as I loose so much data and b). once I've re-installed everything I'm wondering if the problem will just come back again.


What am I going to do next?


I have no idea. My phone is currently pretty useless unless I'm on Wi-Fi.


If I'm going to keep my iPhone need help with this problem please if anyone has any ideas?

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Apr 13, 2016 8:58 PM in response to russelljsmith

I have been having the same issue sort of. I have gone through about 4GB of data in the past 7 days according to my carrier, Verizon, but my usage in the cellular menu only shows 1.4GB for the same period. Contacted apple via chat for assistance and they told me to go to Settings>General>Reset>Reset Network Settings. Did so and will now have to monitor usage via Verizon basically. FYI you will lose any WiFi passwords you have but all the other settings as far as WiFi assist and icloud settings have remained just as they were before. I never had the high amounts of data you spoke of for system services. Hopefully this is a carrier error or the reset will fix the issue.


My details:

iPhone 6s

iOS 9.3.1

except for a few apps I need cellular data is turned off to all the others

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Apr 21, 2016 12:25 PM in response to russelljsmith

HI, I have exactly the same problem. 6gb of data used by documents and sync during a three hour period when I wasn't aware. I went through all the options you did and finally did a reset to a previous backup and deleted my last three new apps. I then didn't have the problem again until this evening where by a data monitor program I had installed informed me that 2gb had been burnt through in 20 min this morning. My usage had not changed.


IM disappointed that I'm not getting any response from Apple other than it must be a setting issue that I'm responsible for. The phone bill is £104 this month. if this continues I will need to change phone


have you got any further?

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May 21, 2016 8:44 AM in response to russelljsmith

Since the end of February 2016, both my iPad (4th generation) and my iPhone 6 plus have been using excessive amounts of data, mostly with respect to Documents & Sync. For about the last month or so, I've been working with Apple Support to try to find out the cause of the problem. After much troubleshooting on my part (Apple wasn't too helpful), I narrowed the cause down to iCloud services, particularly either iCloud Drive or Notes. During my conversations with an Apple representative, he acknowledged that other users are experiencing a similar problem. This week, I discovered that data usage on my iPad and my iPhone went back to normal levels when my 2012 MacBook Pro (15") running El Capitan was in sleep mode (usually, I leave the MBP in an awake state, but this week deviated from that). Long story short, last night I logged out of iCloud on the MBP and so far data usage on the iPad is zero (I haven't used my iPad at all since last night) and data usage on the iPhone is negligible. I'm going to continue to leave my MBP logged out of iCloud for the rest of the day and check my iPhone's and iPad's data levels this evening. If the data levels continue to remain low, I'll log back into iCloud on the MBP tonight or tomorrow morning and see whether the simple process of logging out and logging back in on the MBP resolves the issue. If not, we'll know that something is corrupt or broken with the iCloud services on my MBP. My current theory is that something on the MBP is causing constant updates to one or more of the iCloud services, which in turn is pushing those updates to my iPhone and iPad, thereby causing the excessive cellular data usage.


I would very much appreciate it if those of you who are seeing excessive cell data usage on your iOS device would please try logging out of iCloud on your MacOS device and seeing whether that stops the cell data usage bleeding on the iOS device and then report back here.


Thanks,

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Excessive mobile data (cellular data) usage by Documents & Sync

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