Does Updating Unlocked AT&T Lumia 1520 to 8.1 Relock it?

[foxbat121]

It just shows you that dial ##7820# is not a reliable way to test if a phone is SIM locked or not. I have never heard any GSM phone get re-locked after a firmware update.

 

[Priceless Luigi]

It just shows you that dial ##7820# is not a reliable way to test if a phone is SIM locked or not. I have never heard any GSM phone get re-locked after a firmware update.

Do you know any cases where the phone was relocked?

 

[pankaj981]

Do you know any cases where the phone was relocked?

That really doesn't happen

 

[MDK22]

It appears I stand corrected, wish I had a T-Mob sim to test it.
I will check my wife's (my old L920) phone after her Cyan update, her sister has T-Mob (& the right size sim). I unlocked it before I gave it to her, still have the unlock code.

BTW - I offered her a choice - L1520 or another L920 ... she said ' ... if you want the BIG phone, get it, just hand over yours.'
Only one of the reasons I love her !

 

[badr0b0t]

Why don't you just pop in a nano sim to answer your own question? Nano sim is just $7.50.