T-Mobile miscalculated a forced migration of customer plans and accidentally canceled free promotional lines that customers had earned through previous promotions. The carrier has committed to restoring those lines, but the underlying price increases tied to the migration remain in effect.
The bungled migration affected customers who held older plans with attached free lines, a common promotional offer T-Mobile used for years. When the company moved these customers to newer plan tiers, its systems failed to preserve the free line benefit. Customers discovered the loss when their bills arrived with unexpected charges.
T-Mobile's response included restoring the canceled lines at no charge and crediting affected customers for overages. However, the company did not reverse the price hikes that prompted the migration in the first place. Customers who previously paid lower rates on legacy plans now face higher monthly bills even with their free lines restored.
The incident reflects operational challenges in managing legacy customer accounts during system transitions. T-Mobile maintains millions of customer records with varying plan structures and promotional terms accumulated over decades. Automating migrations across this complexity created gaps where the company's systems lost track of entitlements customers had already earned.
The restoration effort required manual intervention by T-Mobile support teams to identify affected accounts and restore lines individually. This approach, while correcting the immediate problem, exposed the lack of safeguards in the original migration process.
For customers, the outcome is partial. They recover the free lines T-Mobile wrongly canceled, but they absorb permanent rate increases T-Mobile intended to implement. The situation highlights how even when companies fix their mistakes, consumers may still lose ground if the underlying business decision remains unchanged.
T-Mobile has not disclosed how many customers experienced the cancellations or the total value of credits issued.