As ridiculous as it sounds T-Mobile Sim cards, although identical from retailer to retailer , are only as good as the knowledge of the employee who scans it a check out. I purchased 3 from Walmart and neither were ever fully activated and TMobile surprisingly cannot override the Sim card activation. I went back multiple times to Walmart with the Sim cards going through painstaking return and repurchase cycles that inevitably made no difference. Each one of the three I purchased was returned and exchanged twice each because of activation failures. I ended up with three useless sim cards, no refund, no mobile service, and a headache from Walmart blaming TMobile and TMobile blenny Walmart. First one purchased from Best Buy was validated by T-Mobile and my cell phone was up and running before I even left the parking lot. My five stars is primarily for best buys employees apparent elevated skill level in scanning the UPC and properly scanning the Sim card ID for instant activation. I at least take comfort in knowing that I can depend on Best Buy to pick up the slack of other retailers and more importantly TMobile. It's ridiculous that they provide absolutely no support or options unless the retailer has properly activated the Sim card at the time of purchase. Employees at Walmart have no idea how to do it which is surprising because the Internet is riddled with frustrated customers experiencing this same exact issue.