Home Slickdeals T-Mobile Offer: Existing Single-line or New Customers: Get a 3rd Line Free... Slickdeals T-Mobile Offer: Existing Single-line or New Customers: Get a 3rd Line Free via Monthly Bill Credits By ARCOM - 4 July 2020 129 0 SHARE Facebook Twitter Go to the deal page: T-Mobile Offer: Existing Single-line or New Customers: Get a 3rd Line Free via Monthly Bill Credits