What is your phone bill hiding?

What you owe is due when the line goes. Verizon and AT&T put the full remaining balance of every financed phone on the final bill when a line is cancelled or moved, and neither prorates the last month. T-Mobile bills through the end of the month; one cancelled line keeps paying monthly, and only closing the whole account makes every balance due at once.

Credits stop with no payout. A monthly credit against a phone belongs to the line. Cancel it, pay the phone off early, or change to a plan the deal does not cover and the rest of the credits are gone. T-Mobile has applied this to early payoff since June 2024.

Payoff offers pay you later. T-Mobile Family Freedom: up to $800 a line on four lines at most, new accounts only since July 2026, a new phone on their plan and the trade-in of the one you were financing, paid as a prepaid card about 15 days after the trade-in clears. AT&T: up to $800 a line as a reward card 8 to 10 weeks later, your own phone is fine, 120 days and four payments with the old carrier required, clawed back on a sliding scale if you leave within 36 months. Verizon: a $15 a line monthly discount against a competitor bill, no lump sum. The old carrier's final bill always arrives first.

Autopay. Verizon's full discount needs a bank account or Verizon Visa since February 2024. AT&T pays $10 for bank, $5 for cards. T-Mobile pays $5 a line for debit or bank only.

Fees that rise on their own. Verizon Administrative and Telco Recovery Charge $3.78 a line; Regulatory Charge $0.26 from 1 November 2026. AT&T Administrative and Regulatory Cost Recovery Fee $4.99 a line since August 2026. T-Mobile Regulatory Programs and Telco Recovery Fee $5.49 a line from 12 October 2026 unless the plan says taxes and fees included.

Retention. Verizon ended standing loyalty discounts on 1 September 2025; offers now come from the Offers tab, from generating a Number Transfer PIN in the app, or from chat, usually $10 to $20 a line for 6 to 12 months. AT&T: 800-331-0500, say "cancel service". T-Mobile: 611, say you are thinking of leaving.

No. Verizon puts the balance on your final bill. The carrier you move to may reimburse part of it, weeks later, if you meet their conditions.

The credits on that line stop, and at Verizon and AT&T the phone balance is due on the next bill. At T-Mobile the installment keeps billing monthly if the account stays open.

A credit reached its end date, a fee rose on its own, or a change of autopay method cost you the discount. Paste the bill and the first panel tells you which.