Q: Unlocked sprint iPhone 6s on AT&T

Hello KikiMarie,

You should be able to make the switch. Sprint and Verizon uses CDMA and ATT and T-Mobile use GSM. Before you could not make the switch because the networks are two completely different types. Since the iPhone 6s comes unlocked now you can use it on any carrier since it can use a sim card. I am making the switch from Sprint to T-Mobile and they use two different types of networks but T-Mobile said since my phone was unlocked I should be able to. I would think the same works with ATT since T-Mobile is the same network type. Just mention to them you have an unlocked phone and would like to open an account with them and just need the sim card kit. They may just be trying to make more money off of you by making you purchase a phone through them.

KikiMarie wrote:

 

To my understanding the Sprint model supports tmobile Verizon but not AT&T since it's missing the 30 band. Some sources say this wouldn't be enough for it to work at all, however some say this is.

The 30 band that AT&T has exclusive rights to from a deal made back in 2012 has only just begun to be integrated into modern phones. The iPhone 6 did not have this band even on the AT&T model. The lack of this band may be of issue in your coverage area for activation purposes, but that would be a more detailed conversation with AT&T. I would suggest getting assistance from as seniored a department as you can reach within their activation department.

When you insert an AT&T SIM what message do you get on the phone?

KikiMarie wrote:

 

I receive an activation error, however I just tried with Verizon and got the same error as well. I'm now thinking the model of the phone isn't the issue (despite an apple employee telling me this, but I've gotten conflicted answers from them) and that it's possible Sprint is not being truthful about unlocking my phone.

You can Contact Apple for support and service - Apple Support and confirm as to whether or not the iPhone was unlocked. You should be able to call in and explain that you have just had your iPhone unlocked through Sprint, but are having trouble using it on a supported carrier. What does the iPhone Profile list my phone as being? Is it showing up as unlocked or is it still locked? In the event that you haven't already done the steps listed in the following article, I will just post this as well.

How to unlock your iPhone for use with another carrier - Apple Support

Follow these steps if you have any issues or if you see this message in iTunes or on your device:

"The SIM card inserted in this iPhone does not appear to be supported. Only compatible SIM cards from a supported carrier may be used to activate iPhone. Please insert the SIM card that came with your iPhone or visit a supported carrier store."

1. Restore your iPhone to factory settings.
2. Contact your carrier to make sure that the unlock was applied in your carrier's system.
3. Restore your iPhone from a backup.

The band won't affect activation, which is done via the voice side channel. The only issue with the band is that the phone may not support LTE in some areas, but it will still work.

The exact wording of the error message is critical to knowing where the cause lies. If the message is "the SIM is not supported" that means that Sprint did not unlock it. If the message is anything else then the problem is not with Sprint.

Lawrence Finch wrote:

 

The band won't affect activation, which is done via the voice side channel. The only issue with the band is that the phone may not support LTE in some areas, but it will still work.

That's true. That band is for data. If all other steps have been done though that I listed in my most recent comment, contacting Sprint is still going to be the next step here if they didn't unlock it. If they did, then AT&T would be the next to contact.

Sprint has a history of being highly uncooperative when it comes to unlocking. They will either send you a useless "unlock code," or they will unlock it for international use only.