T-Mobile is offering a FREE $250 Prepaid Mastercard when you bring your own device (BYOD), activate a new line of service, and port in a number for a limited time. To get his deal: activate a new line of service by porting in a number from a qualifying US wireless carrier, then register for your rebate here with the promo code: 2020BYOD1. You must complete 30 days of activation. This same offer and promo code also work for current Sprint Customers and they can file their rebate here. Limited to 4 rebates per account. May not be combined with some offers or discounts but many readers have reported it working with the FREE line that T-Mobile is offering for accounts with 2 or more lines.