Expected to be announced on Oct 4.
Switch and add a new voice line of service to existing or new accounts and,
trade in a iPhone 6S to Xr for $700 off, or
trade in a Xs/ Xs Max for $1000 off
a new iPhone XR, Xs, or 11, 11 Pro, 11 Pro Max.
You will get the fair market value on first bill for the traded-in phone and the rest is credited over 24 months.
Number ported-in must not be from T-Mobile and its direct MVMO in the past 90 days, e.g. Metro will not be eligible, but Google-Fi which uses T-Moible's network is.
Most importantly: Discount is limited to ONE line per account. One can only trade in one phone for this discount.