T-Mobile is forcing a massive migration of its longest-tenured customers onto modern service tiers. The carrier plans to retire aging legacy plans, some of which have remained active for up to 15 years. These outdated contracts originated during the 3G and 4G eras, long before the current 5G infrastructure was established across the country.

Most users will see a price increase as part of this transition. While the company claims some customers will see no change, the average hike sits at roughly $4 per line. T-Mobile intends to move these users to newer plans that include a 5-year price guarantee, though they have not specified which exact tiers affected customers will receive.

Impacted subscribers should watch their inboxes for an official notice. The company plans to send email notifications providing two weeks of notice before changes take effect in mid-July. Because T-Mobile has not listed the specific legacy plans being retired, customers must verify their current billing status to avoid unexpected charges on their next statement.