Having a corrupt IMEI can be a real pain. It seems to happen randomly to flashaholics, and having the radio go down on a cell phone really defeats the purpose of owning a cell phone. Thankfully it is not problem that is overly common. Unfortunately, it does still happen. For AT&T Samsung Galaxy S III users, and in some cases users of the other US Galaxy S III variants, there are not one, but two ways to prevent this problem. There is now a tool that will back up your IMEI without much difficulty and a manual guide for those who prefer to dive into the nitty gritty.
The tool was developed by XDA Forum Member <:GeeK:>, while the manual method was written by XDA Senior Member Peoplearmy with some credited help from others. Both methods eventually perform the same task, which is backing up and restoring your IMEI, and each has its set of pros and cons. Without a doubt, the manual way is more involved. However, it actually supports all 4 US variants, although it hasn’t had to be tested on the Sprint version yet. The tool involves a much shorter and more simple—root free—process. Both methods also have tutorials on how to get your IMEI back if it is already corrupt. Between the two, they address every conceivable IMEI concern for the US Galaxy S III variants.