Recent rumors were suggesting T-Mobile was going to go after other carrier ETF fees as part of the Uncarrier 4.0 plan. And while T-Mobile has yet to offer any official details on what can be expected, it seems AT&T is going after T-Mobile now. AT&T has announced a limited time offer where they will be giving T-mobile customers up to $450 per line to make the switch.

This offer kicks off today, January 3rd, and right from the beginning we learn the potential $450 credit depends on getting service and also trading in another carrier device. Details coming from AT&T touch on how T-Mobile customers can trade-in their current smartphone for up to $250. Of course, the trade-in value will depend on the device you are trading.

While that last bit holds true, further chatter from AT&T mentioned how “many of the latest and most popular smartphones will qualify for a value of $250.” The remaining $200, to bring the total of $450, comes for the actual switch. To this point, those looking to switch from T-Mobile t AT&T will be able to get $200 credit per line when they transfer to AT&T using an AT&T Next plan or buy a handset at full retail.

These new AT&T customers will then be able to choose one of the Mobile Share Value plans. These plans include unlimited talk and text and some data. The amount of data will vary from plan to plan, but prices here begin at $45 per month with 1GB of data.

Given AT&T has seemingly jumped on an opportunity to go after T-Mobile users — it should be interesting to see how T-Mobile will respond. We are expecting some further Uncarrier news, the 4.0 portion of that plan, but so far we have yet to learn a specific timeline as to when those details will be announced. For now, it looks like the ball is in the hands of T-Mobile.

SOURCE: AT&T (1), (2)