T-Mobile today announced new handset and service promotions that offer new phones for low monthly payments with one big catch: the equipment installment plan runs for 36 months. That means it will be three years before customers pay off their device, rather than the customary two years. The basics are these. Beginning October 19, customers can trade in an eligible phone for a new Samsung Galaxy S8, S9, Note9, LG G7, LG V40 ThinQ, and others for payments as low as $10 per month. T-Mobile hopes customers taking advantage of this promo will jump on the T-Mobile Essentials plan, which provides a family of four new phones with unlimited service for $40 per line per month, or $160 total. This breaks down to $30 per month per line for service and $10 per month for device payments. The actual device payment may be different. Customers who want the T-Mobile One plan will need to pay another $10 per month per line, or $50. This deal requires auto-pay. Eligible phone trade-ins will be credited to customer accounts monthly over a period of 36 months. The maximum trade-in value is $360 per device, but that will depend on the trade and its condition. T-Mobile didn't immediately list a set of devices eligible for trade-in. The trade can be applied to the purchase price of most phones LG sells, including the forthcoming iPhone Xr.