T-Mobile Data Breach History

This page tracks the T-Mobile data breach history and cybersecurity incidents affecting T-Mobile (United States). BreachHistory currently indexes 15 publicly disclosed or catalogued incidents spanning 2006 through 2023, with approximately 320.8 million records reported as exposed across all indexed events. These totals may include overlapping datasets or third-party estimates and should not be interpreted as unique affected users.

The T-Mobile breach timeline includes major data breaches, cyber attacks, data leaks, credential exposures, API abuse, and other security incidents. Each incident provides details on the estimated records exposed, attack method, affected data types, and supporting public sources. Currently, 0 incidents are company-confirmed, while 2 remain unverified claims pending independent verification.

Largest T-Mobile Data Breaches

The largest indexed incidents include the 2021 — T-Mobile: Hacking, 76,000,000 records, the 2018 — T-Mobile: ZDNet's Zach Whittaker reports:A bug in T-Mobile's…, and the 2017 — T-Mobile: A bug on T-Mobile‘s website may have allowed…, along with additional historical incidents involving exposed passwords, public databases, and large-scale data scraping. Record counts originating from threat actors or leak sites should be treated as estimates unless confirmed by T-Mobile or a regulator. Below is the list of large data breaches:

• 2021 2021 — T-Mobile: Hacking, 76,000,000 records — about 76.0M records exposed · Catalogued incident
• 2018 2018 — T-Mobile: ZDNet's Zach Whittaker reports:A bug in T-Mobile's… — about 74.0M records exposed · Catalogued incident
• 2017 2017 — T-Mobile: A bug on T-Mobile‘s website may have allowed… — about 69.6M records exposed · Catalogued incident
• 2021 2021 — T-Mobile: Hacking, 45,000,000 records — about 45.0M records exposed · Catalogued incident
• 2023 2023 — T-Mobile: Hacking, 37,000,000 records — about 37.0M records exposed · Catalogued incident
• 2006 2006 — T-Mobile, Deutsche Telekom: Lost / stolen device, 17,000,000 records — about 17.0M records exposed · Catalogued incident
• 2018 2018 — T-Mobile: Hacking, 2,000,000 records — about 2.0M records exposed · Catalogued incident
• 2020 2020 — T-mobile: Hacking, 200,000 records — about 200.0K records exposed · Catalogued incident

What Information Was Exposed?

Depending on the incident, exposed data may include email addresses, names, physical addresses, health and medical (PHI) records, and other personal information (PII). The exact data varies between incidents, so review each breach page before assuming your information was affected.

T-Mobile Data Breach 2026

At the time of this update, no T-Mobile data breach has been catalogued for 2026. New incidents are added as official disclosures, regulatory filings, or credible cybersecurity reports become available.

What To Do If You Were Affected

If you believe your account may have been involved in a T-Mobile data breach, change any reused passwords, enable multi-factor authentication (MFA), monitor your account for suspicious activity, and be cautious of phishing emails or fake breach notifications.

This T-Mobile breach history is maintained by BreachHistory using public disclosures, regulatory filings, security research, and clearly labelled third-party claims. For the complete breach timeline, records exposed, incident details, and AI Breach Risk Score, explore the sections on this page.