T-Mobile’s new billing rule hits credit card users where it hurts — their discount

What you need to know

• As of October 24, you can no longer get T-Mobile's $5-per-line discount while using a credit card for the actual payment.
• The carrier tightened its billing logic so the discount only applies when the actual payment comes from a debit card or bank account.
• T-Mobile will notify affected users via text message when their discount is removed for the upcoming billing period.

If you’ve been cleverly gaming T-Mobile’s AutoPay system to keep your discount and your credit card rewards, your free ride just hit a wall. T-Mobile is officially closing the popular loophole, and the change is effective starting October 24, 2025.

T-Mobile has officially ended a long-standing workaround that allowed some customers to score the $5 per-line AutoPay discount while still paying their bills with a credit card. As reported by The Mobile Report, users who prepay their bills using ineligible payment methods will lose their AutoPay discount for that billing cycle.

The change puts an end to a payment workaround that many savvy subscribers had been using to enjoy both T-Mobile’s monthly discount and credit card perks like cash back or travel points.

Previously, customers could set up AutoPay with a debit card or bank account to qualify for the discount, but then pay their bill early with a credit card. The system would still show an eligible payment method and apply the discount, even though the actual payment did not qualify.

T-Mobile's system now catches you

T-Mobile is now tightening its billing logic to ensure the discount only applies when the actual payment is made with an approved method. The company says customers who prepay their bill partially or in full using a credit card or another unsupported option will automatically forfeit the discount for that month.

The policy has been in place since 2023 when T-Mobile officially excluded credit cards from AutoPay eligibility, but this recent update closes the technical gap that made the loophole possible. Affected customers will start receiving text notifications informing them that their AutoPay discount has been removed for the upcoming billing cycle.

To keep getting the $5 per-line discount, customers must use a debit card or bank account as their payment method and avoid making early payments with a credit card. If you prefer paying with a credit card for the rewards, you’ll need to decide whether those perks are worth giving up the recurring discount.

For families or multi-line plans, losing that $5 per line can quickly add up, potentially costing an extra $20 or more each month, depending on the number of lines on the account, as pointed out by one subscriber on Reddit.

For now, there’s no indication that T-Mobile plans to extend credit card eligibility again, so if you want to keep saving on your bill, sticking with a debit card or bank account is the only way to go.