T-Mobile says glitch stripped free-line credits from some accounts

T-Mobile says technical problems caused some customers to lose free-line discounts after the company moved them from older wireless plans to newer ones. The error matters because some longtime subscribers were already facing price increases tied to the forced plan changes, according to Ars Technica.

The company told Ars Technica that the missing free-line credits were not intentional and that affected accounts are being corrected. T-Mobile said the promotions remain valid, discounts are being restored, credits will be backdated when needed, and accounts are being reprocessed.

T-Mobile also told Ars Technica it is looking into reports that some customers were wrongly charged for Hulu after the migration. The company apologized for the confusion and said it would fix the problem for customers.

The billing complaints followed T-Mobile’s recent decision to retire older plans and automatically place customers on newer rate plans. In late June, T-Mobile told media outlets that some customers would see no bill change while others would see a modest increase, and that migrated customers would keep existing benefits while receiving network and service improvements.

Ars Technica reported that the plan changes have been contentious because some customers are being charged up to $6 more per line. For customers with free-line promotions, the temporary loss of those credits could create much larger bills unless corrected.

Complaints surfaced on Reddit and were also reported by The Mobile Report, which said it heard from several users who said free lines did not transfer to their new plans. The Mobile Report also said some customers saw an added hotspot-data charge on their new plans, increasing bills by as much as $15 a month.

T-Mobile has offered free-line promotions at different points, Ars Technica reported. One March 2025 promotion, described by The Mobile Report, allowed customers with at least 10 years of account history and at least two paid lines to add another line at no extra monthly charge.

Some customers said those promotions made up a large part of their accounts. One Reddit user said an account that had three paid lines and six free lines for about $50 a month showed a bill of more than $300 after being moved to T-Mobile’s Experience Signature plan, with no free-line credits listed.

Another Reddit user said the removal of free-line promotions increased a bill by $200, according to Ars Technica. A separate user said T-Mobile support could not restore one free line and instead offered a year of credits after saying the line was ineligible on the new plan.

The migration is part of a broader back-end cleanup inside T-Mobile. Ars Technica cited a leaked email from T-Mobile Chief Operating Officer Jon Freier saying the company is eliminating about 1,100 legacy billing codes as it retires old plans.

Freier’s email said nearly half of affected customers would see no price change, while others would pay up to $6 more per line, according to Ars Technica. He also said customers moved from older 3G- and 4G-era plans would receive more premium data, more high-speed hotspot data, better international coverage and a five-year price guarantee.

Fierce Network reported that cutting 1,100 billing codes would leave T-Mobile with fewer than 100. The report said the codes are billing-system rules tied to products and plan features, and that reducing them could make it easier for T-Mobile to update its website and app.

The latest complaints come after earlier backlash over T-Mobile’s 2024 decision to raise prices for some customers who had signed up under lifetime price-lock promotions, Ars Technica reported. Customers filed Federal Communications Commission complaints and a class-action lawsuit, which Ars Technica said remains pending while T-Mobile seeks to force the plaintiffs into arbitration.

This story draws on original reporting from Ars Technica.