Some Verizon Wireless customers are reporting an interesting issue with their new iPhone 5 handsets. Even when their phone is connected to Wi-Fi, LTE is being consumed when they unlock their device. In an age that no longer includes unlimited data plans for most users, this could certainly pose a problem.

According to an active post on the Verizon discussion board, this isn’t an isolated incident and in some instances, the data usage is fairly large.

Says scarletknights928:

This morning when I got the phone, I only had used .046GB, and I’m always browsing the internet/checking Facebook/blogging/etc. When I got home I connected to our Wi-Fi and downloaded some apps. It was on Wi-Fi the entire time, but the usage went up to .050, which was weird. Then I drove back to my dorm, connected to my Wi-Fi here, barely used any apps and it just went up to .060.

Of more significance is what happened to oscargee, who said:

I have the same exact problem and I learned the hard way after using almost 1 GB in data watching an hour-long movie on Netflix.

We’ve confirmed that for some users, the iPhone 5 does connect to LTE even when a Wi-Fi connection is available. Still, this didn’t happen for everyone. In total, two of the three Verizon iPhones we tested connected to LTE when being unlocked. All three were tested in different areas of the U.S.

According to one poster on the discussion board, the same thing happens on the iPhone 4S/4 with 3G. However, we could not duplicate this on any handset.

For those users concerned that their iPhone 5 is using LTE when it shouldn’t be, we suggest turning off the connection. To do so, go General > Cellular on your iPhone and turn Cellular Data to the off position. This will restrict all data to Wi-Fi, including email, Web browsing, and push notifications.

We have yet to hear back from Verizon regarding this issue. When we do, we’ll update this report. In the meantime, we’d love to hear from you. Have you experienced this problem too?