I'm looking at selling my old smartphone from AT&T. A co-worker is willing to buy it, but I need to find out if T-Mobile's network would detect the phone being a smartphone and automatically upgrade her plan to include a data plan. I have heard that AT&T's network will do this, but I need to know if T-Mobile will also. She doesn't need nor want the data plan, so just need to know this before continuing. Thanks.