At the beginning of the year I lost my job and had to file bankruptcy. Unfortunately AT&T was included in my list of creditors and now I'm stuck with a iPhone Xs Max that is just sitting in a box. Is there any way to unlock this phone so I can use it with another carrier?
I am assuming the answer will be "no", because I still owe on the phone (even though I filed bankruptcy). However, I didn't think it would hurt to ask.
Third party unlock services.
Just keep in mind that these services use inside contacts/software to submit your unauthorized unlock. The fee you pay reflects the risk of discovery. With AT&T there is also a heightened sense of security because a few years back there were six employees that were caught doing this. They had installed software on internal systems to allows unlocks to proceed after hours and that's what tipped off IT. All six employees were fired and sued, as was the unlock service and AT&T went back and relocked those devices that they had unlocked for profit.
That's how the system works with third party unlocks. So, if that does not offend your moral code this is an option.
Alternatively, you can find a SIM Interposer. Gevey, TurboSIM, R-SIM, etc. These are devices that you insert your SIM into and then the entire things goes into your SIM slot. They fool the device into thinking it's unlocked and functional. But they are not true unlocks (if you take it out, the device is still locked). The downside to these are that some of them require you to be jailbroken and all of them are sensitive to the version of iOS you are running. You cannot just update whenever you feel like it.
