Why doesn't my Verizon SIM work with my unlocked ATT iPhone 5?

someoneinpnw

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Verizon SIM does not work with unlocked ATT iPhone 5

2 year ATT contract on my iPhone 5 just ended. Requested and received instructions on how to use iTunes to unlock it. The unlock process went fine and I even got a message in iTunes saying: "CONGRATULATIONS! YOUR IPHONE HAS BEEN UNLOCKED!".

Then it was just like someone let air out of my balloon when I inserted a Verizon SIM and my iPhone said NO SERVICE. (I borrowed it from a friend and it was a working Verizon SIM).

Called ATT but the ATT rep. was clueless and he just wanted to put the blame on the Verizon SIM.

Does anyone have any idea as to why my iPhone does not recognize the Verizon SIM?

Appreciate your time...
 

HankAZ

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Re: Verizon SIM does not work with unlocked ATT iPhone 5

2 year ATT contract on my iPhone 5 just ended. Requested and received instructions on how to use iTunes to unlock it. The unlock process went fine and I even got a message in iTunes saying: "CONGRATULATIONS! YOUR IPHONE HAS BEEN UNLOCKED!".

Then it was just like someone let air out of my balloon when I inserted a Verizon SIM and my iPhone said NO SERVICE. (I borrowed it from a friend and it was a working Verizon SIM).

Called ATT but the ATT rep. was clueless and he just wanted to put the blame on the Verizon SIM.

Does anyone have any idea as to why my iPhone does not recognize the Verizon SIM?

Appreciate your time...

The iPhone 5 was CDMA (Verizon and Sprint), and GSM (AT&T and T-Mobile). These technologies are incompatible with each other and the phones cannot be used on the other networks - CDMA devices only on CDMA networks; GSM phones only on GSM networks. So there is no way to use a VZW iPhone 5 on AT&T (or T-Mobile), or an AT&T iPhone 5 on VZW (or Sprint).

WIth the release/adoption of LTE by the major service providers, using devices on all the LTE networks became possible.
 

someoneinpnw

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Re: Verizon SIM does not work with unlocked ATT iPhone 5

thank you, HankAZ. From what you explained, even now it's unlocked I will still have to use a SIM from a GSM carrier. What are other carriers beside T-Mobile and ATT that use GSM?
 

HankAZ

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Re: Verizon SIM does not work with unlocked ATT iPhone 5

thank you, HankAZ. From what you explained, even now it's unlocked I will still have to use a GSM carrier SIM. What are other carriers beside T-Mobile and ATT that use GSM?

A Google search of wireless carriers in your area may give you the best information. I did find this in Wikipedia - cannot vouch for its accuracy, but it should help:

List of United States wireless communications service providers - Wikipedia, the free encyclopedia
 

by1333

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Re: Verizon SIM does not work with unlocked ATT iPhone 5

Have you called verizon to activate?


Sent from my iPhone using Tapatalk
 

someoneinpnw

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Re: Verizon SIM does not work with unlocked ATT iPhone 5

my intention was to verify that my iPhone was indeed unlocked. I was not aware of CDMA vs. GSM issue. At this point I don't know who I will switch over to.
 

by1333

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Re: Verizon SIM does not work with unlocked ATT iPhone 5

my intention was to verify that my iPhone was indeed unlocked. I was not aware of CDMA vs. GSM issue. At this point I don't know who I will switch over to.


Gotcha, next time Ill make sure to "read the thread"...
 

robbrick

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Re: Verizon SIM does not work with unlocked ATT iPhone 5

Hank is right. However, there's a bit more to this. The Verizon version of the iPhone HAS CDMA and GSM chips inside, hence a world phone. The ATT version is a GSM only phone. Unlocking the ATT version allows one to use on another GSM service, like TMobile but not on Sprint or Verizon.
 

kch50428

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Re: Verizon SIM does not work with unlocked ATT iPhone 5

Hank is right. However, there's a bit more to this. The Verizon version of the iPhone HAS CDMA and GSM chips inside, hence a world phone. The ATT version is a GSM only phone. Unlocking the ATT version allows one to use on another GSM service, like TMobile but not on Sprint or Verizon.
My guess is the guts are there - just disabled by a firmware/carrier setting level... and carriers are the ones with the ability to enable/disable those parts - not Apple.
 

IAmSixNine

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Re: Verizon SIM does not work with unlocked ATT iPhone 5

The Verizon iPhone has the sim card for the LTE network. Voice still works on the CDMA network. The IMEI number (for CDMA) and SIM number (LTE) are paired together in Verizons system. When the phone powered on with the Ver sim card it was still missing the IMEI info. At best you might have been able to get data, assuming the right protocols were enabled. Meaning LTE only.
Now if you pop in a TMO sim in there all would be good. Both TMO and ATT are GSM carriers, so the TMO sim chip carries the info for it to work with voice and text. OR if you went over seas and got a GSM carriers sim.
 

gazoo2010

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Re: Verizon SIM does not work with unlocked ATT iPhone 5

If you go onto the Verizon Wireless website and click "learn more about the Verizon Plan", then hit "I'm not with Verizon" under lets go,and then click "I have my own device". Once there you will have a screen that allows you to enter your phones IMEI number and it will tell you if the device is compatible with Verizon's networks.

From my experience, the ATT iphones are not compatible. The Unlocked iPhones and the TMobile iPhones are compatible (as you are paying the full price for the phone). I just tried the site and my Tmobile iPhone 6 and 5s are compatible....

Hope this helps.
~S
 

Hernandezrafael

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Jul 12, 2016
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Re: Verizon SIM does not work with unlocked ATT iPhone 5

2 year ATT contract on my iPhone 5 just ended. Requested and received instructions on how to use iTunes to unlock it. The unlock process went fine and I even got a message in iTunes saying: "CONGRATULATIONS! YOUR IPHONE HAS BEEN UNLOCKED!".

Then it was just like someone let air out of my balloon when I inserted a Verizon SIM and my iPhone said NO SERVICE. (I borrowed it from a friend and it was a working Verizon SIM).

Called ATT but the ATT rep. was clueless and he just wanted to put the blame on the Verizon SIM.

Does anyone have any idea as to why my iPhone does not recognize the Verizon SIM?

Appreciate your time...

Hi I'm having the same problem, I have a working phone from Verizon and my sister gave me an at&t phone, so went ahead an unlocked it o?r my Verizon SIM card in it and it just said emergency calls only. I asked the agency who gave me the code to unlock the phone why tve phone wasn't reading my Verizon SIM card they told me that it was because Verizon was not a GSM network. So at&t isn't compatible with Verizon wireless network.
 

Kyle Gehman

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[The answer you got was and is totally WRONG...You cant use a verizon sim in an unlocked gsm iphone...but you can use an AT&T or Tmobile or any other GSM sim in an unlocked CDMA phone...once the gsm side of the iphone is unlocked on a CDMA phone you can use it for any GSM...And over seas...I never post anything on these sites...but I am tired of people answering questions that they have no Idea what they are talking about....