NEW! 2 lines of UNLIMITED 4G LTE data on T-Mobile for just $100/mo. UNLIMITED 4G LTE data must be added to all lines on your plan. Additional lines $40/mo. per line. IT’S BACK! T-Mobile's 1GB of 4G LTE option is increased to up to 2.5GB 4G LTE data per line (for the same price) until 2016 when you buy 4 or more lines. Need more data? Get up to 4.5 GB of 4G LTE data per line until 2016 for $10 more per line! Limited time offers. Unlimited 4G LTE Promo: Two-line min. family plan req’d. 2.5GB & 4.5GB offers: Four-line min. family plan req’d. After 1/2/16, 2.5GB of 4G LTE data automatically reverts to up to 1GB of 4G LTE data per line, 4.5GB reverts to up to 3GB 4G LTE per line.