Costco T-Mobile BYOD $100 Costco Cash Card Thumb Score: 0 From 9/27/19 to 10/3/19 Costco seems to be offering a $ 100 Costco cash card for a BYOD on new T-Mobile activations. Seems like a sweet deal since they also waive the activation fee. http://membershipwireless.com/content/offer3 Slickdeals Hot Deals Forum