However, there will be some limits for frequent travelers. Any trip abroad needs to be six weeks or less, and customers need to spend at least half their time in the U.S. in any three-month period.
T-Mobile also announced on Wednesday that it had upgraded its network at home with high-speed wireless services in areas with coverage for just over 200 million people, roughly three months ahead of its year-end deadline for the milestone.
T-Mobile, the No. 4 U.S. cellphone carrier, has been trying to differentiate itself from bigger rivals by shattering longstanding industry practices and calling itself the "Un-carrier."
The company began in March by dropping conventional two-year service contracts in favor of selling phones with installment plans. In July, it introduced a program that lets people upgrade phones more frequently - up to twice a year. AT&T, Verizon and Sprint have since followed with their own frequent-upgrade plans.