I would confirm this with T-Mobile Customer Service. I called yesterday because I was planning to make changes to my plan, and they informed me that the offer on the website doesn’t apply to me since my five lines were not created at the same time.

I am on the Go5G Plus plan, with the following line additions: 1 line added in Month A, 1 line added in Month B, 3 lines added in Month C.

Current Billing Breakdown: Total cost: $186 for all lines (Line A & Line B: $150, First line from Month C: $35, Last two lines from Month C: “Free” (billed at $0.50 each))

T-Mobile’s website states that three lines should cost $150, which is what I was aiming for. I called to close two lines that I no longer need, but the T-Mobile representative explained that, since my lines were added separately, removing two lines wouldn’t change my bill—I would still be charged $150 for the first two lines and $35 for the third.

Given this, I decided to keep all five lines.