T-mobile - iPhone 16 Pro ON US with New Line and Eligible Trade

P988 is not for upgrades. But eligible to add a free line.

Can be 5 lines or have to be 4 lines?

Contact us before cancelling entire account to continue remaining bill credits, or credits stop & balance on required finance agreement is due (e.g., $999.99 – iPhone 16 Pro 128GB). Bill credits end if you pay off device early. Tax on pre-credit price due at sale. Limited-time offer; subject to change. Qualifying credit, service and trade-in (e.g., Save $1,000: iPhone: 13 Pro / Save $830: iPhone 12 Pro / Save $415: iPhone 6; in any condition; must provide IMEI) required.  $35 device connection charge due at sale. Up to $1,000 via bill credits; line with promo must be active and in good standing to receive credits; allow 2 bill cycles. Max 4 discounted devices/account. May not be combinable with some offers or discounts.

Not useful for simple choice

TXXX is a liar. Still fighting with them about my last year's deal. They told me that I was qualified for the 4 lines on us, but after a year, I am still paying the full price for 3 of them