The iPhone 5 uses Cellular Data over WiFi?

I tested my phone by reseting my cell usage and then watching youtube videos and running speed tests while on wifi and the my phone used a ton of data. The data is reported correctly on the phone, I checked with Verizon and they show the same usage on thier end. I went into the Apple Store and explained the situation and the genius told me that is was probably because I restored from a back up instead of starting my new phone fresh. So I asked if they could restore my phone to default while I waited. They restored my phone to default and I ran me test and it happened again LTE data used and this time on Apples wifi network. They then gave me a new phone and I ran the same test on their wifi and it happened again. So then I got to talk to the super genius who told me he would open an escalated ticket with apple and they would get back to me in 48 hours.

My phone 5 is on Verizon, I wonder if the same issue happens on AT&T (or any other GSM network).

I a on ATT with an iphone 5 and my cellular data since 9/21 is 3.3gb, tons more than ive ever used in my life and with no explanation. My theory is that there was a feature in an ios6 beta called "Wifi + Cellular Data" where the wifi signal was still always supported by cellular if the wifi signal weakened. It doesnt look like the feature made it to the final IOS 6 build but i think that there are pieces of the code that havent been properly cleaned up and are being activated. This is either being exacerbated by the wifi issues or causing them IMO.

You should check with your provide and think about the data plan based on your usage. If you plan to transfer tons of data over a cell network it may be a good move to consider the pricing and plan.

The only problem is choice of data plan.

I cant believe I went over my 2gb cap. I had a Droid Bionic with 4G LTE from Verizon and never even came close to 2GB because I have so much wifi available. Verizon customer service was terrible, saying that am doing stupid stuff like streaming pandora or something on my data plan all night. I have wifi at home, school and the only time I use data is when I'm either driving or getting a coffee. Its gotta be the iphone. Might be the new Siri or iOS Maps??? It cant just be me. as im reading all of your posts.

P.S. I check my data usage religously every week and it went from saying I had .7 GB of usage to 2.3 GB after just 6 hours of usage while im on wifi. I event took screen shots of the before and after.

My iPhone 5 said that I had used 1.5GB of data between 6:22pm and 6:32pm last night while I was listening to an already downloaded podcast.

Me too. iPhone 5 on Verizon. 1.5GB in less than a week. Never used 1GB in a month with iPhone 4 on ATT. Data usage stats show that nearly all of it is while I am supposedly connected to strong home or work wifi. I've disabled cellular data for now.

Same thing happening to me on AT&T. Fix?

I'm not having that issue at all.

My data has remained normal when I'm in the house or at work on WiFi.

I have an AT&T iphone, but I'm not in an LTE area.

Glad I saw this thread. Turned off Cellular Data while on wifi and the problem stopped. I then tried making a phone call and it worked. When I sent a text, it said it didn't go through, yet I got a reply from the person. Then I texted them back with no error message.

To people just seeing this: when on wifi, turn off cellular data or risk massive overages on your data plan.

I am on Verizon with an iPhone 5 BTW.

Hate to be the bearer of bad news, but the same problem is happening with my iphone 4 after I updated to iOS6.

Last month on 5.1.1 I used 647MB of data using it quite a bit. One week into my new billing cycle with a fresh install of iOS6 from the start and I'm at 1.5 gigs of data usage, and I swear I'm using it less!

This is definately going to be causing people lots of grief. For those in Canada who only have the 500MB plans, we're going to have a ton of unsuspecting users who are going way over their data usage without even realizing it.

I purchased a new Verizon plan with two brand new iPhone4's on Wednesday. Both iPhone 4's are using celluar data instead of using my reliable wifi network -- 4MB's of data in two days. The phones indicate they are connected to the wifi successfully. I only noticed because both phones sat idle on my desk after I set them up, but when I went to register "My Verizon" online I noticed I had already used 4MB's of data. Checking the log provided by Verizon showed the many (40+) 10-50K cellular data uses since turning on and updating the new phones.

After calling Verizon, technical support said this is a growing problem and that they are trying to convince Apple that there is a problem by testing some phones and documenting their results. Verizon support told me to go into Settings - Cellular and turn off cellular data when I'm at home in range of my wifi network. The technician indicated this would absolutely prevent the phone from using my metered cellular data.

I wonder how many people maybe out there who don't realize their phones are using cellular data instead of wifi? It's going to be a big surprise when the bill arrives.

We're on this list, too... since turning off cell data we've kept it under control. Verizon is no help. They don't even understand their own billing system. Anxiously awaiting a fix and considering returning the iPhone5s. We have a few days left to decide.

My wife and I got iphone 5's and she barely uses her data on her phone. plus battery life is terrible limiting the usage of the phone as well. Well we are 11 days into our new plan and she has used 1 gig and I'm almost at 2 gig :-/

Why would you return the phone? Apple eventually will fix the issue, but in the mean time, you have a work around when on wifi. Just monitor your usage in the mean time.