Is your iPhone eating up your data allowance?

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When UK iPhone carriers announced that they would be doing away with unlimited data plans I had a minor panic. I’m on unlimited broadband at home and it’s always a comfort to know that whatever I do online I won’t hit a download limit. If there was to be a limit on my iPhone use wouldn’t there be a chance I’d end up hitting it?

Well, when I checked my monthly usage it was only about 300mb – well under the 500mb minimum level set by my provider (O2). So I wasn’t worried. However, several of my friends and other people from around the Internet are reporting hugely increased data usage on their IOS4 iPhones… that’s iPhone 3GSs running v4+ of the iPhone OS, or the iPhone 4 itself. How big is the increase? Well, as an example, Zoe reports somehow using 450mb in just six days. That comes out at 2.25gb in a month! What’s going on?

I decided to track my data use for a few days by downloading DataMan (pro – there is also a lite version) from the app store. My results are by no means conclusive, but I hope you’ll find them useful.

Location services?

The iPhone’s location services uses a few different methods to work out where you are. There’s GPS, triangulation via mobile masts, and checking any nearby wifi networks against a database of their locations. If you have an app running that uses location services (you’ll see an arrow at the top of your screen) there will most likely be some data use. But 75mb in a day? I don’t think so – there’s no way that amount of information is required just to tell where you are. To test this I went out on a long walk with Runkeeper Pro running… which tracks where I am, maps it for me, and even lets me upload photos I’ve taken while out and about. I uploaded a photo just to make sure I was using everything properly, and I should mention that DataMan also requires location services to be switched on.

Result? 1mb of cellular data was used. It doesn’t look to me like location services is the culprit. However, if you are really concerned about data use, or just worried that your iPhone might be spying on you, you can switch location services off in the General tab of the Settings screen.


photo One suggestion is that it’s the new multi-tasking ability that’s eating into data: apps running in the background that are continuing to send and receive data. This is certainly possible – I often minimise apps and want them to keep doing whatever they’re doing – but unless you specifically close them those apps will remain in the background even when you’re finished with them… days at a time. If this is a concern to you (and it is to me, but usually because I think having too many active apps will slow my phone down) double-tap the home button on your iPhone, then hold your finger on any of the active app icons. They’ll start to “jiggle” and a red X will appear on each icon. Tap the X and the app will be properly closed down.

I strongly suspect that background apps are the main culprit for excessive data use and would recommend manually shutting anything down that you’re not using. It’s just a shame that the method for doing so is a bit fiddly.

But I’m on WiFi! Why am I using cellular data?

Yep, I wondered how I had managed to use cellular data at home given that I have wifi too… but the iPhone switches wifi off when it’s in sleep mode. So if your screen is locked you’re just on the cellular network and any apps that request data at that time will do so via cellular instead of wifi. I think this is another good reason to make sure you’ve closed them down by the method above.

What if I go over my data allowance?

This is the real question: what happens if I use more data than I’m allowed? That depends on your carrier, and you should phone them up to find out. Be warned, however, that a few people I’ve spoken to say that when you call O2 you don’t get a very helpful answer… their operators don’t seem to know whether you’ll be cut off, speed limited, charged a one-off fee or forced to take out an extra bandwidth bolt-on. If you have any experience that can clear that up I’d love to know about it – please tell us in the comments.

Over to you…

I was out and about all day with my iPhone 3GS, running the latest iPhone OS. I had location services on, two twitter clients running in the background (one of which is advert supported), e-mail automatically downloading every 30 minutes, and I downloaded a few app updates over wifi. In total I used 8mb of cellular data and 100mb of wifi, but I suspect that’s because I’m quite picky about closing background aps.

How about you? Are you experiencing huge amounts of data use? If so, how many apps are you running in the background? And are you on an IOS 4+ iPhone 3G/3GS, or an actual iPhone 4? Let’s try and work this out – leave any relevant info in the comments and we might notice a pattern.

Data use monitoring, including geotagging to tell where you used what, is available via DataMan from the App store.

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  1. For more info about what happens if you go over your data limit on O2, visit this page:

  2. Johnny Ixe says:

    Hi Chris

    Thanks for using DataMan. I’m glad that DataMan has helped you in your investigation.

    Good news. DataMan 2.0 is approved and available in the App Store now :)

    Please update and give us a review in the App Store.

    The new DataMan app makes background geotag and location services optional. This will satisfy users who want to save every tiny bit of battery power. Plus, a new great way to view your usage everyday. Now you can see your daily usage pattern. The new DataMan adds support for iPhone 3G.


  3. Krishna says:

    I have stopped all the notifications, not browsed at all for the past 3 days. But whenever i get a mail the data usage is incrementing by 1mb. The size of the mail is less than 100kb.
    What could be the issue?

    • shmoe says:

      I’m having the same problem, checking mail uses about 500~1000KB data..
      and it checks like every 10 minutes.. even though I set it to check hourly :(…
      any solutions?

      • Backpacker57 says:

        Another note from the Apple fan club that just doesn’t like Phantom Data usage showing up on their AT&T bill— suggestion to reduce usage:

        Be sure to keep your TRASH, Junk and Sent folders that are SYNCHED UP with MobileMe empty— or cleaned out as much as possible; a User reported that he/she reduced their iPhone data consumption— but did not solve the problem!

        There are many examples of reducing data usage that involve HUMAN INTERVENTION and THOUGHT! Not exactly a GOOD idea for a TECHNOLOGY SOLUTION to have so many caveats!

  4. Katie says:

    I’ve only had my Iphone 4 for 5 days and I’ve already used 130mb of my 200mb data limit and the only thing I have done is run apps. I haven’t even gone on the internet once and I’m trying to figure out how I could possibly be using so much data.

    • Hi Katie – could it be due to downloading the apps? Or did you do that on a wifi connection?

      • Katie says:

        Yes, I’m pretty sure you just solved my problem! I hadn’t realized that it uses cell data unless you have wifi. Thank you! I’ll be sure to look into getting wifi.

  5. I also have the problem of some app using cellular data to access the Internet even though I’m connected to wifi. Vodafone “couldn’t” tell me which app was at fault. Since then, I’ve set Cellular Data and Enable 3G (found in Settings > General > Network on the 3Gs) to “Off” in the hope that this will finally stop the unnecessary charges to my call credit. It’s worth a try.

    • That’s very odd. Do you know if it’s happening when the phone is on standby? I’m just thinking that I read an article that said the iPhone doesn’t stay connected to WiFi when it’s asleep, but reverts back to cellular. I’ve noticed that when I wake unlock my phone it does take a little second to reconnect to the WiFi, so it seems to be true.

  6. Iqbal Bedi says:

    I have just signed up with three on their 1G per month allowance and I have been caught out using over 1G in a month – which is ridiculous as I have not been streaming. At most its facebook and email. But I do notice small emails increment data usage up by almost 1M. I suspect something odd going on here. I have now switched off email for a day to see what happens. I also sync my calendar but I cant see that using Mbs of data… Is anybody aware of an app that tells you which Application is using up the bandwidth to really isolate the bandwidth eater?

    • That’s the second person who’s reported that their e-mails seem to be using much more bandwidth than expected… wonder if that’s a pattern emerging.

      I’m afraid I don’t know if an app that will tell you how much data is being used by which app. I contacted the guys being DataMan today and they say they’re working on incorporating that in a future version… but it’s not there yet.

  7. Iqbal Bedi says:

    Hi Chris,

    After going in circles 3’s billing said that my usage was through the night (whilst asleep) at regular patterns and so seemed like a backgrounnd app using data. Tonight I will ensure there are no apps running and selectively switch of 3g, email, calendar sync etc..but if Dataman can help pinpoint the culprit app that would be awesome – I would pay for that !

    • Hi Iqbal,

      It seems the iPhone doesn’t maintain a WiFi connection when it’s on standby so any data usage at night would go via cellular. Not ideal, is it? There’s more discussion here, including a suggestion to leave your phone plugged in at night, but I’m guessing it’s likely you already do that?

      If/when DataMan add app-specific monitoring I’ll be sure to post it on the site.

  8. I desperately search for the problem solving and your article only strengthens me in this search…:-)
    My iPhone 4 consumes about 1MB of cellular data per day. I have switched off everything I can think about: mails, calendars, contacts 9everything lost, but it doesn’t matter – need to find!!!), location services… There are no additional application installed, I switched it off to restart from scratch….
    Nothing helps!
    If I switch off cellular data in Settings, and then switch it on, I can see that each approximately 5 mins it exchanges with about 8KB of data.

    If somebody know what can be done here, i shall highly appreciate an advice.

  9. Backpacker57 says:

    You may want to visit the Apple Discussion Forum–

    and try some of the recommendations: such as OPTING OUT of the Apple program under iTunes by connecting your iPhone to your Mac or PC and right clicking on the device– RESET WARNINGS and then resync your iPhone and you will get a message pop up do you want to send diagnostic info to Apple? Select NO or NO THANKS.

    This reduces data but does NOT eliminate the data overage charges.

    Get DataMan so you can fight your carrier and remember to SYNCHRONIZE your billing dates from your carrier with DataMan so you get an accurate picture of your data usage compared to you Billed Data Usage.

    I do not think there is a fix as of yet or that even Apple or the carriers even acknowledge an issue—-

    • Thanks for the info – if the diagnostic data is being sent at night, and the iPhone is always on cellular data when it’s asleep, that might explain a few things.

  10. Backpacker57 says:

    As I just noted above:

    Another note from the Apple fan club that just doesn’t like Phantom Data usage showing up on their AT&T bill— suggestion to reduce usage:

    Be sure to keep your TRASH, Junk and Sent folders that are SYNCHED UP with MobileMe empty— or cleaned out as much as possible; a User reported that he/she reduced their iPhone data consumption— but did not solve the problem!

    There are many examples of reducing data usage that involve HUMAN INTERVENTION and THOUGHT! Not exactly a GOOD idea for a TECHNOLOGY SOLUTION to have so many caveats!

    Come one PEOPLE! These are supposed to be SMARTPHONES!


    They’re not as SMART as you were led to believe. APPLE and the Carriers must pony up!!!!!

    The Apple UG was written about with a summary of causes to the problem— at:
    iPhone Data Usage: Fighting the Man

    But who has time to fiddle with all this?????????

  11. Not sure if anyone picked up on this, but Zoe, who originally alerted me to the high data usage, has managed to cut it down a fair bit:

  12. Backpacker57 says:

    It reduces some traffic but still does not fix the problem(s)

    Apple needs to design in users not having to do anything and users should know exactly what they are paying for— and the ramifications of using apps, tools and when and why they are being charged for data. Then, how about security?

    The phantom usage is still unresolved.

  13. pcunite says:

    Please tell the DataMan programmers to make their program turn off cellular data on a threshold setting. That is the real answer for me.

  14. Fluidus says:

    It seems this issue of erroneous data usage on the iphone is becoming ever greater.

    I have used an Iphone 3GS since July with no data issues until the last couple of months. Apparently my data usage has jumped from 45mbs a month to 500mbs last month and over my 1GB allowance just twelve day’s into this month with very little change in my usage?? When attempting to find out what could of caused such a leap in usage, ones contract provider (3) drew a blank ? However I was told my phone transfered 12.66 mbs at the exact time I turned the phone on this morning and again at regular intervals throughout the day when I was clearly not using any cellular data. The largest being a transfer of 159.13 when I was not even with the phone. The real puzzle is that all apps are properly closed emails are retrieved manually and there is certainly no data being transfered that I have requested! Due to the advice above I’ve put the DataMan app to use so at least I can more effectively monitor the data transfers.

    This does all coincide with the OS4 update? Perhaps a link or just coincidence?

    • Backpacker57 says:

      OS 4.2 update was to fix 40+ security issues. One user commented his data usage is in line after updating—- see Apple Discussions

      Then- more input on phantom data usage being caused by apps, cookies and marketing pinching information about users and then forwarding it on. This may be another contributing factor too.

      • Fluidus says:

        Thanks for the reply, unfortunately the update has made no difference to my iphones erroneous data upload/download. My phone has had cellular dat switched off for some time due to it using my full monthly allowance within a week, during which time I monitored my wifi usage to be clear on how much data I use when on specific apps and email, no where near my usage limit. After switching on Cellular data the unidentified upload and download started. This really does need to be sorted out, another complaint to ‘Apple’. If we are looking at a security ‘threat’ then perhaps it’s time to retire the ‘iphone’ and return to a simple mobile!!

  15. shmoe says:

    Hello everyone,

    I don’t know if this is new or not, but I just noticed recently that facebook app. got this “Shake to Reload” I think it’s new.. mine was on so everytime my iphone was shaken it would update newsfeed in facebook, make sure to turn it off from settings.

    good luck!

  16. At last i have found people who are having the same issues as me…….i am with Vodafone and pay £35 per month for a 1gig allowance. My contract started in September where i used 128mg of my allowance…October 256mg. December is a completely different kettle of fish. I use my phone to browse the net and read Sky and BBC news updates…. So far this month i have apparently used 1.6gig of data in 3 weeks. 456meg of that was used in a single day on the 24/12/10…..i was lucky i was sat down when i looked at my online bill……Having contacted Vodafone they were less than helpful. They stated it may be an app i have bought / downloaded or my e mail settings. I have tried everything to rectify this problem including removing my e mail completely and removing all my apps i have downloaded, but to no avail. I have downloaded Dataman (New version) which is helpful in keeping a track of the unauthorised downloads. Vodafone have reimbursed my charges but would like to ask if anyone knows of a solution in sight from Apple in respect of this. The best advice from Vodafone was ‘Switch off your 3g’………… about burying there heads in the sand. Any advice would be appreciated. Cheers

  17. My iphone 3GS managed to use 1Gig of data allowance in 7 hours on the 24th December whilst in standby and in the background. This triggered an SMS from vodafone UK stating that as I was going over my allowance, I would be charged a further £5 per 500Mb. Needless to say I was unimpressed. On checked the settings – usage I could see the data counter incrementing. Turning the phone off and on again stopped it, but I’ve no idea what was behind the problem. I am using version 4.2.1 (8c148a).

    I’m interested to hear if anyone else has experienced this rate of usage?

    • DaveP says:

      I have a Iphone 4 latest firmware and had exactly the same problem in Dec went over 1gb allowance my normal monthly usage is 300-350mb could see no reason for this so reboot phone again yesterday after cheching usage first thing in the morning then at lunch time I had used 10.3mb sent and 450mb received I had no apps running in the background and do not use push mail luckly I spotted this again rebooted phone and touch wood its ok again (for how long I do not know) there are other people reporting this as well on other websites this is just one I have posted on apples website as well. This needs sorting quickly

    • Dave

      I have the same issue as you. I received a text from Vodafone on the 20th December 2010 saying I was about to go over my limit. As my phone had sat on my desk unused I thought it odd. I checked my unbilled usage and there was, accourding to Vodafone data usage every minute of 2931KB (or there abouts) from 7:31 am until I rebooted the phone at 16:13 at which point it stopped. I did not have any apps running that I can remember. I have now been charged the £5.00 for extra usage. I have contacted Vodafone Customer Support, who dont seem to have a clue and have said that they will get the ‘people who work on computer systems’ to call me… still waiting. I will lodge a complaint with vodafone when I get my bill and request that they give me further details or what this data consists off.

      I have since downloaded DataMan and have noticed that despite there being no apps every 10 minutes there is a small data upload varying between 1kb to 36kb. I have turned off eveything I can think off from push mail to location services in the thought that I could slowly turn on each service and then monitor the data usage.

      I am on 4.2.1 (8c148) Carrier = Vodafone UK 9.0
      Hopefully I can get through to the ‘people with use computers’ and get to the bottom of this. I suspect it is either a fault / bug with OS or on the cell network or both. I do find it strange that you have experiance the same issue at a similar date i.e 24th when mine was on the 20th. very odd.

      • I’ve managed to get Vodafone to look further into my iphone using 1Gig of data in 7 hours whilst not in use. I mentioned I had come across others on here that seem to have had the same problem. Are there any more?

        • Dave

          Which department did you speak too at Vodafone. I have been trying to get them to look at this by going through customer services and it’s like hitting a brick wall. They dont seem worried and say that Vodafone can’t help, go and speak to Apple. According to Customer Services, Vodafone dont retain any details of the WAP activity like URL info so they cant trace where the traffic has origionated or destined to.

          Let us know what Vodafone say and how far you get.

        • Sharon says:

          So happy to find this thread. I have exactly the same problem with Vodafone. Weird data usage stared Dec 24th in the middle of the night with no apps running. Only knew due to texts advising that I was going over my limit and being charged.

          Customer services useless, although they did acknowledge that data usage was “odd” and “ongoing” during my conversation with them. They suggested I turn off Data and visit a shop (presumably to prove that nothing was running)

          Shop manager agreed to refund charges but could only suggest turning off data.

          Visit to second shop & the manager seemed more willing to help. Switched her sim with mine but data kept jumping up on my phone. Her suggestion is to take off all apps and see if there is still a problem – if there is then she will take it up with the powers that be – and if not, reload the apps a few at the time to ID the culprit.

          Am about to do as she suggests and will keep you posted


  18. Backpacker57 says:

    There are two new class-action lawsuits that were filed against Apple and the app makers in late December, 2010 — one for violation of federal wiretapping laws and the other for violation of user privacy—

    The WSJ reported on the app privacy issue prior too—

    While iPhone OS 4.2.1 fixes 41+ issues including security and has made some users data usage more realistic (those that track with DataMan and view their online usage and iPhone usage) find the data consumption realistic—- there are still many others that are going over the data allocation in their monthly plans and remove ALL apps and disable email push and still getting charged—-

    The OS 4.2.1 does not apply to first generation iPhones BTW.

  19. Hello, guys.
    I followed the instructions provided here several times – to reset the warnings in iTunes and reject the request to send data to Apple.
    Absolutely no influence. The same 1MB of data traffic in about an hour. :-((((

    Are there any other ideas!?

  20. Just forgot to mention that I have 3 iPhones 4 under control, two of them do not have even 1 installed application – everything is exactly as received from the porvider. All have the same traffic problem.
    Just for now we keep “cellular data” OFF all the time, except the moment when we really need to do something.
    This way we hardly utilize 10% of our prepaid traffic volume.

  21. John ALLEN says:

    Just to confirm another case for an iPhone 3GS in Luxembourg, provider is Luxgsm.

    My contract includes 2GB/month and up to now I have never been anywhere near the limit – a few hundred MB at most.

    When I checked usage from 1 Jan to 12 Jan, I was already at 4GB for only 2 weeks, and as I’ve been at home with Wifi for most of this period the extra cellular data usage is very puzzling.

    I installed DataMan yesterday and I’ve been removing recent and suspect Apps to see if I can if I can cut the data traffic down quickly. So far I’ve removed

    – Living Earth
    – Facebook
    – Calvetica

    DataMan showed that a lot of the downloads took place at night when I was asleep.

    As of now the traffic has definitely declined to a normal level.

    There is a real need for a way to monitor traffic broken down by App.

  22. iPhone customers on O2 are reporting exactly the same issue – me included. This probelm has arisen for me since December. I typically use 2 to 300MB of my 500MB cellular data allowance each month and reset my usage stats at the start of each billing period. I suspect this issue coincides with iOS 4.2 as I’ve used iPhones on O2 for 2 years with no previous problems with high data use.

    Yesterday my iPhone 4 used 100Mb in an hour – all while the phone was not being used. I received an O2 text alert that I had used 80% of my allowance and then another 3 hours later saying I had used 100%. The usage stats only record 134MB down and 5Mb up for the entire billing period so far. When I pointed this out to O2 customer support they immediately offered me another 500MB bolt on for free and opened a Network Investigation.

    I’ve since installed DataMan, disabled Cellular Data other than when it is required, close all running apps after use and have done the Reset Warnings with iTunes.

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  1. […] morning Chris posted this on Geek-Speak following a conversation I had with him on Saturday. Very […]

  2. […] It’s been interesting to read the conversation around the post I wrote in October about iPhones using excessive amounts of cellular data. […]