Sprint is offering a free iPhone 11 to new customers when they trade in an iPhone 7 or newer. The old iPhone can be in any condition but must be unlocked. The deal requires a new line activation and an 18-month "lease" that costs $0 after a monthly credit is applied. Verizon is offering a similar deal of a free iPhone 11 for new customers with trade-in. T-Mobile is offering 50% off the new iPhones with trade-in.