T-Mobile denies claims of massive customer data leak

Cybercriminals recently claimed they stole personal information from 64 million T-Mobile customers, including names, birth dates, addresses, phone numbers, and other sensitive details. This data supposedly appeared on a dark web forum in early June 2025, raising alarms about a possible major breach in the U.S. The information was said to be fresh, dated June 1, 2025, which added some weight to the hackers’ claims.

T-Mobile quickly responded, denying the breach. The company told outlets like The Mobile Report and PhoneArena that after reviewing a sample of the data, it doesn’t believe the information came from its systems. However, some details, like phone numbers, weren’t part of past leaks, which makes people wonder if this could be new.

Experts note that hackers sometimes mix old and new data to make their claims seem more believable or to use in scams like “credential stuffing.” This news comes at a tough time for T-Mobile, as it’s still dealing with fallout from a 2021 data breach, with settlement payments just starting to reach affected customers. Another breach so soon would hurt the company’s reputation, especially after it promised to strengthen its security.

Cybersecurity experts are urging T-Mobile to double-check its systems and warn customers to watch for identity theft risks, like phishing scams or unauthorized account access. For now, T-Mobile stands by its claim that no breach happened, but the situation has left many customers uneasy.