Data - what uses Data?

@anniec Which programs did it say were using your data?

Was WiFi assist using much of your plan?

@Gary L

The screen shot is old.  I used the iPhone 6 Plus as my spare on my other line for a few months last year.  

I have an Apple router (Airport express), but that may or may not be why my phone stayed connected.  I have done several things to flout the data saving rules, and still don't use significant amounts of data.  I've gone a month with wifi off, all apps on, background data on and still didn't exceed 3 GBs a month. 

I've  done this on multiple phones.

The one exception, On my Note 3 I deliberately left my security app running in the background all day (8 hours) on high resolution.  When I turned it off, I had used 5 GBs of data in one day, which (for the record) did not report on ATT until about 6 hours later, at midnight, when my phone was connected to home wifi.

I have 3 incidents of where a faulty phone or app caused data over use.

Each time a new iOS is introduced, a few customers have reported data overage.  The iPhone 4S when updated to iOS 7 literally broke the wifi radio on the phone.  

(The 4s was a more than few years ago...)

When new iOSes come out, lots of apps get updated if people are updating those (with cellular updates allowed) they are going to get significantly more updates than usual and result in more apps being downloaded (more data).  

When people update and it chokes and they have to do a full restore or they go get their iPhone replaced and start the iCloud restore BUT leave WiFi before it's finished restoring a lot of data it still does quite a bit of "stuff" on cellular.  We tracked a buddies data (he called me to test the phone before he left the store so we had a reference point) and then he walked out and the data climbed we could see it on-line later.  

If I had a new iPhone it would be updating thousands of e-mails and my messages in the background. The first time I launched my news reader it would be updating thousands of articles the first time I launched it (all the categories I haven't read, new articles and the 1000+ that I've favorited in the past).

These have to do with things that happen around iOS updates (not the updates themselves), but not necessarily WiFi assist.

@Peanuts

in settings, data usage/cellular data.   

Pictures above are for iPhone.  

Pictures in this post are android. 

Select an app and restrict background data.

When I travel to Canada, I'm usually on one of those Passport plans, so I use a highly-detailed data-usage tracking tool(s), there are some really good free ones out there.

The ones I've used will break it down to the kb, split by WiFi/Cell, and by service/app, they seem to slice/dice the data almost any way you want.

When I set this up, a few years back, I just read some reviews, picked the one that had the best options for me and had great reviews, and it's never failed me.

While this is on Windows phone, I'm sure there have to be some similar iOS apps, that do the same thing, for free, or close?  Even if they're $1 or similar, it'll pay for itself rather quickly...

Your use may not have changed, but phones do change.  HD screens and location services, etc.

Software updates, etc.

You android phone keeps a record of data used and for what.  Look in settings, data usage and see what is using Data and in what amounts.

Android phones can also limit and warn you so you don't go over (c. Below).  Check the box and set the limit a bit under your actual allowance.

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@MsEmmasNana wrote:
I too am being charged extra 15 dollars or more for so called over usage. ..nothing has changed since I started using an android phone in 2008, this seems like another means for customers to be charged so ATT can fill their pockets. .. I always use the WiFi at the gym, or any public business while I'm shopping, and always use my home wifi... I don't stream music, movies, etc... I'm 60 yrs old and I do prefer texting over chatting on the phone... so why am I being charged extra $$$ for unlimited text/talking... I turn unused apps off, ... Thanks from Colorado

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Go to your data-uage settings, per @lizdance40's post, and tell us what your high-use items are, and how much data?

Screenshots are handy for this, it's usually pretty easy, varies by model/OS.

With this info, we can help you sort this a bit more, there's likely an app installed and using data, possibly you just didn't realize it was high-use (like the security example above), or it came with another app, and you just need to disable it.

Help us to help you ;-]

*If this (or another post in this thread) fixes your problem/issue, please mark it as solved, and I'll tag it, to make it easier for others to find the answer(s). Thanks.