Branched to a new discussion.

Mysterious cellular data usage in early morning


    I just used up all my 4GB of cellular data for this month.  This had never happen before. In the pass, the most I had ever used was about 2GB.

    When I check my data usage detail, I found there are some over 100MB usage everyday around 5-7am, while I was sleeping.

    I need to know what is causing this and how to stop it.

    I am using iPhone 7 on ios 11.1.2


      All replies

      • snn555

        Your iPhone may disconnect from WiFi during sleep. Also iCloud updates and backs up usually in the early AM.

        • tmo_mike_c

          I think snn555's idea about iCloud updates being behind this is possible. You could check the data usage on the phone itself. It probably won't show the time when the usage happened but you could use it as a way to check the data usage for certain apps that appears to be more than usual. Please keep us updated on this.

          • tmo_chris

            Just checking in here to see how things are going. Were you able to identify which apps were using your data?

            • magenta3593694

              I just had this happen today as well. 


              My data usage report is showing ~1.195 GB between 0000 and 0430 when the phone was not being used and was on my home wi-fi.


              This will likely cause my high speed data plan to run out several weeks before the end of my billing cycle.  This is quite frustrating.

              • inie

                has this been solved? I am having the same issue. called T-Mobile about it and they gave me a ticket number. They wanted to get back to me within 3 days but when I hadn’t heard from them after 8 days i called them back to follow up and the guy said they investigated and it had something to do with the towers in my area. Then he said he would transfer me to the tech department. Then some other guy ( not from the tech department) picked up and had no idea what I was taking about. So I explained myself again saying that I am running out of my 6GB data plan two or three weeks into the new cycle. most of the data (between 75-130mb) occur at night like 4-6 am. I’m on wifi when I’m at home and at work I don’t use my phone, I also  I turn my data off to figure out what’s going on. He told me the time that shows on the usage is pacific so for me it would be 3 hrs ahead, 7-9 am. Well I’m in Ohio so pacific time would be 3 hours behind which is 1-3 am and yes i am definitely asleep that time.  He offered me a $10 credit for this cycle which I gladly denied because that’s not gonna stop me from paying for data that I am not using!    NOT a happy customer T-Mobile!

                  • tmo_chris

                    Re: Mysterious cellular data usage in early morning

                    Hey inie 


                    Data usage recorded by the network only looks for what is requested by your SIM card. In the comments above, the other user was going to look into a data usage monitoring app to see if he could see what app on his phone was requesting the data but never reported back with any findings. If this is something that is happening every night, you can try placing your phone in airplane mode, turning on your Wi-Fi and enabling Wi-Fi calling so you can still call and text. This will essentially prevent your phones SIM card from requesting any data from the network. If you still see usage, we can reopen that ticket for you and see that your phone was not requesting any data from the T-Mobile network.

                  • fetacheese

                    So I just had the same thing happen. Went over 3gb for the first time in the history of having data to use. Checked my usage for the past 2 months and big chunks are being used between 3-6 AM. I turn my phone OFF every night before I go to bed. Called suppprt and they were no help, saying there's only so much they can do to check what is causing this mysterious usage due to privacy issues. I get that, but it is creeping me out that something or someone is using my data in the middle of the night. There has to be an explanation since I'm obviously not the only one this is happening to. Sure wish I knew. Been a customer for over 15 years and never had any issues until this. I'm going to monitor it for the next month or two and if there's still no clear answer I'm gonna move on.

                      • inie

                        Yea T-Mobile reps are pretty useless. the one dude that was “taking care“ of this issue told me it is the early morning hours because it shows pacific time so for me that would be 3 hours ahead. I payed close attention to it and it’s actually true, however, it’s sucking up way too much data. I work full time and don’t even have cell phone service at my job and I commute 3 hours a day so I rarely use my phone and at home it’s on WiFi ALWAYS!!! My friend has an 8 gb plan that she shares with her mom and brother from Verizon and at the end of the month they still have 3gb left. She has better reception with Verizon so she literally uses her phone at work all the time. Honestly I only stay with T-Mobile because they  have an awesome oversees plan so I can use it whenever I visit home, but after my trip in summer I’ll probably switch providers since this is ridiculous!

                        • tmo_chris

                          fetacheese - The timestamps for the data usage are in PST on as inie pointed out but if your phone is showing usage when it is off, there is definitely something wrong as this should never happen. If you check your usage and adjust it to your timezone, is this usage occurring when your phone is completely powered off?


                          inie - We definitely do not want to lose your business over this. If you feel that your data is being used incorrectly, this is something that we can definitely look into. Since your concerns is not that usage is occurring when you are not using the phone but rather a lot of data being used, I would suggest taking a look at your phones built in data usage meter to see what apps are using the most data. There are some third party apps that could allow you to drill that info down further to see if it is occurring in at specific times but this would be something you would need to download from the Play/App store.

                        • djluciano

                          i am on the verge of walking out the T Mobile door after some of the worst phone support ever.  My son's iPhone is showing huge log files, at hours where he is asleep, the phone is connected to wi fi.  I suspected malware, but no one would give me any log info besides what i can see on the t mobile site.  i am having him do a factory reset next.  my frustration is with the lack of knowledge or understanding from the rep.  literally spat back the same words over and over, put on hold a bunch of times and no help at all.  YES, we know apps like facebook can run in the background, but not pulling 400+ mb of data at a clip at 4:57 am or some other bizarre hour.

                            • tmo_chris

                              How long as this been happening for? Are you able to see what specific app is using this data?

                                • djluciano

                                  Hi there.  I figured would reply directly at this point.  Thanks for helping troubleshoot.  My frustration is really that I was trying to do the same, and rule out anything like malware by getting some research/information based on the data usage (seeing if someone could tell via logs what was being accessed).  The offending app looks like Safari, which is odd as he uses Chrome.  Last night, we did a factory restore and shut off data.  But, I still see info in data access (although it may be delayed)




                                  Obviously we are not happy that the data limit is already reached  for the month, from activities not generated by the customer.




                                  This is the 774 number on the account.  Entries like those below are concerning.  This is the second month I noticed it.  Not sure if prior months (I can look) had similar calls, but, didn’t hit the data limit so didn’t research further.  Thanks much.





                                  05/17/2018, 03:44 AM


                                  Internet Access




                                  129.1611 MB



                                  05/15/2018, 04:23 AM


                                  Internet Access




                                  295.9941 MB