The iPhone 5 uses Cellular Data over WiFi?

I think a "finicky" wifi in IOS 6 is the culprit here!

I do not have a cell data plan (in fact, I even have it switched off from the network settings) and since upgrading to IOS6 internet over wifi has been extremelly unstable, with the connection being constantly dropped.

So I am guessing that if your wifi connection is also being intermitently dropped the phone will have to resort to the cell data to download whatever content...

I'm also seeing cellular data being used instead of wifi. We have three iPhone 5's and they all exhibit this issue. For a test, last night before bed I reset the data statistics on one phone, made sure the phone was on wifi (the access point was 8 feet away), and in the morning it had used 300KB of data. That is not a lot of data, but why did it use any? I also had every setting I can find set to not use cellular data.

The previous night my son's phone showed that it used 2GB of data while he was sleeping. That was the first night we had them and was, to say the least shocking. Verizon has since rest our data back to zero, but we are a little shell shocked!

I have seen the same issue on the two iPhones 5's I have. I agree with the spotty wifi connection theory. The phones don't seem to stay connected to wifi. So when it drops the wifi connection LTE takes over and racks up the cell data consumption. I work from home on wifi all day and my first full day of work after getting my new phone it used 30mb. It should have used 0 for this time period. I just upgraded from the iPhone 4 and this want not an issue. Apple there is an issue please fix it!!!

It would be interesting if you disabled cellular data and then tried to watch YouTube vid to see if it plays with just wifi enabled

Also if you can access your router when you have cellular data enable d and you look at YouTube vid have a look at your router to see if your phone is one of the attached devices

While trying to sort out poor battery life I have just realised that I have this issue too. Despite being connected to wifi I my iphone 5 is showing continual small increases in cellular network data use. I always close apps proprly, have the bare number of location services on, have painstakingly set up iphone 'as new' rather than from back up. This is not happening with my iphone 4 which has ios6 loaded and is set up in an identical way. If I switch off cellular data and reset the stats then all is fine, but obviously this is far from ideal.

So, in summary, iphone 5 using cellular data when on wifi, iphone 4 doesnt! The two phones are on my desk next to me.

Hmmm....

Something is definitely not right here but I'd like to propose another theory. It's possible that it isn't being measured properly. My usage data shows almost 400mb used for cell data but checking Verizon's account page shows only 80mb which is in line with previous usage on my AT&T 3GS. Something is clearly not right.

It does play Youtube videos with just WIFI enabled.

I somehow managed to burn up 1.8gb of data over 5 days on my iphone 5. This had never happened in my past 4 years of owning an iPhone. Apple has no idea what's causing this. I can't believe I'm about to hit my full months data limit in 6 days when I connected to wifi 75% of the day. My data app says 1.2gb came from OS services. And a half gig from twitter. This is just extremely weird and costly. Verizon will not reimburse me for data either.

Well, add me to the list of people with the same problem. In 6 days I've used over 6 gigs of data. I've been on wifi over 80% of the time. This is crazy! There is definitely a problem here, I used less than a gig monthly wen I was on the iPhone 4. The iPhone should not use any cellular data if its connected to wifi. Hope this gets fixed soon its a very costly bug.

Add me to the list. I am seeing the cellular data counter increment even when I am on a very solid WiFi connection. Apple had a feature in iOS where you couldn't disable the "feature" of using cellular in the event your Wifi wasn't responsive. Sounds like they need to either fix this or bring back the abiliity to turn it off.

Personally if I am on my home's Wifi and the iPhone doens't like it for whatever reason I'd prefer it not to connect.

I have the problem too. We lucked out, because since we merged our bill with FIOS our billing month reset today. We were at 1.2 gig of usage in four days, which is close to a normal month's worth of usage for us.

Yesterday I did absolutely zero streaming, sat on WiFi all day long except for ~40 minutes in the car (where I listened to a pre-downloaded podcast) and I still used 30 meg of cell data. That means I'll be 1 gig in the hole over a month, before I've actually done anything useful on LTE. Big problem.

For now I'm just going to turn cell data off when I'm on WiFi. It's a PITA, but better than paying overage charges.

It's not a reporting problem, since the Verizon app confirmed the data usage.

Add me to this list...I agreee with the flakey Wifi connection in the phone. I have 1 bar of cell reception at home and when I try to read my mail or do anything on the internet my phone just spins and won't load. If I force the phone to use wifi by running SpeedTest app everything loads instantly.

At work I have great cell and wifi reception and the same thing happens. I'm lucky enough to have unlimited data so I can solve it in this case by turning off the Wifi and using the cell signal.

This is ubsurd and needs to be fixed immediately. My phone is practically unusable at home.