iPhone 5 Won't Connect to LTE At All

I'm having the same issue. Under settings I switch on/off the LTE and it will show LTE for a brief moment but then goes back to 4g. Need help, anybody know how to fix this?

Wow. I'm having same issue. Please post if you get a fix and I'll do the same. Wonder if it's an added account thing? Did you add a line? For my house, my wife has no problem connecting her new iphone 5 to LTE and I haven't connected once. very frustrating.

ha. made an appointment on wed. as well. will keep looking for answers but i think we might be SOL. someone thought it might be a SIM card issue. no matter what happens, i refuse to let apple tell me to talk to ATT.

This same thing is happening with Verizon iPhone 5's as well. My iPhone 5 goes from LTE to 3G and vice versa. When other people with LTE phones are in the same room, they'll have stable LTE signal, while my phone will either go back and forth, or will have 3G only. I have to manually turn LTE off, on, off, on, off, on, continuously until LTE actually comes back. Sometimes, depending on the strength of the signal, it will simply fall back to 3G. It's almost like that's where the phone is most comfortable and it actually prefers to stay off LTE.

Since the same thing is happening with AT&T iPhone 5's, I'm going to assume this is not an AT&T or Verizon network issue, it's an Apple issue. As to whether or not it's software or hardware related, I'm not sure. I'm inclined to say it's hardware related because Apple has been known to screw up when it comes to making antennas for their phones.

Here's Apple's "Troubleshooting a Cellular Data Connection" guide:

http://support.apple.com/kb/TS3780

Hopefully this will help.

I had the same problem. I had an iPhone 5 purchased through AT&T and my wife had an iPhone 5 purchased from Apple's store (both in that 45 minute pre-order window). The one from Apple would never ever ever connect to LTE and would have data issues on 4G that the phone from AT&T didn't seem to have. Finally got around to diagnosing it some more and found that if I swapped sims, my phone started working on LTE and my wife's dropped to just 4G.

Called AT&T tech support and they somehow reset things in their system / sent new settings to the phone. After they did this, I was told to power down, wait 45 seconds, then power up. When it came back up, I had LTE for the first time ever. Hurray!

I have an LTE issue is I turn it off (to save battery) and then turn it on later: sometimes LTE doesn't come back or, worse yet, I get 'AT&T' with no 4G or LTE and data doesn't work. Consistent fix for me is to turn LTE back on and power off/on via holding sleep button.

I hope what happen to you is the same that hapened to me. I got my iPhone 5 and was on 4G. Later i discovered that the problem was AT&T, the person that actived my account never moved it to the LTE network. As I undertanfd this doesn't happen automatic, so check with AT&T to make sure your account is on the LTE network.