Originally Posted by sabrewulf
I'm already an AT&T customer and I found a Bold on eBay that the seller listed as "unlocked." It's an AT&T Bold. If I were to upgrade the OS down the road.. It shouldn't matter right? Can someone explain to me what exactly is done to unlock and how it affects the phone besides being able to use it on other networks. Would upgrading the OS "lock" the phone to the original carrier (AT&T)?
An unlock will release your phone from the carrier that issued it. It will allow you to use other carriers by switching the SIM card. Since it is a GSM device you can only use it on GSM carriers. Once it's unlocked upgrading or downgrading the OS will have no effect on it. As Penquin stated "Unlocked IS unlocked".
Be careful and read the before you buy sticky at the top of the Buy, Sell, Trade forum here at BBF. Good tips for making a smooth purchase!