T-Mobile is automatically migrating some long-time customers from legacy phone plans to newer plan options, according to multiple reports. The changes affect “thousands” of subscribers, with some customers expected to see an increase in monthly costs. Across the outlets, the potential price bump is described as roughly $4 per line, though the exact impact depends on the customer’s current plan and line count.

The migration is described as starting in July, as T-Mobile retires certain older plan offerings and places affected customers onto current alternatives. Instead of requiring customers to manually select new plans, the move is characterized as automatic, meaning subscribers may notice changes when their billing updates.

The reports focus on the possibility of higher monthly bills for some users, but do not describe widespread service changes or additional benefits for all impacted customers. Customers who are moved are effectively transitioned to T-Mobile’s current plan lineup, with pricing reflecting the newer options.