BreachCensus

T-Mobile

United States of America

T-Mobile is an organisation in Massachusetts. It appears on the Massachusetts Attorney General breach-notification register, the Delaware Attorney General data security breach database and the Wisconsin DATCP data breach list with 5 confirmed incidents; the most recent notice was filed on January 19, 2023.

Data as of October 17, 2026.

Sources

Confirmed incident

US-WI

Occurred
November 25, 2022
Disclosed
January 19, 2023

Timeline

  1. January 19, 2023
    Reported to regulator Regulator

    WI AG breach notification: an unknown number of Wisconsin residents affected

    source

Litigation

  • Possible litigation — multiple candidate dockets found, not yet resolved to a single case.
What a Wisconsin notice means

Governed by Wis. Stat. §134.98. No state agency must be notified. Affected individuals must be told within 45 days, and the national credit bureaus too when 1,000 or more people are notified; DATCP lists breaches reported to it or found to affect Wisconsin consumers.

Note: the count is Wisconsin residents only when published, not a total; many notices do not include one.

Wisconsin breach-notification register ↗

Confirmed incident

US-MA

Disclosed
March 8, 2022

Timeline

  1. March 8, 2022
    Reported to regulator Regulator

    MA AG breach notification: 1 Massachusetts residents affected

    source

Litigation

  • Possible litigation — multiple candidate dockets found, not yet resolved to a single case.
What a Massachusetts notice means

Governed by M.G.L. c. 93H. Notice to the Attorney General is required for a breach affecting any number of Massachusetts residents' personal information -- the statute sets no minimum count.

Note: the count is Massachusetts residents only, not a total.

Massachusetts breach-notification register ↗

Confirmed incident

US-DE

Occurred
August 12, 2021
Disclosed
August 19, 2021

Timeline

  1. August 19, 2021
    Reported to regulator Regulator

    DE AG breach notification: an unknown number of Delaware residents affected

    source
  2. August 19, 2021
    Reported to regulator Regulator

    DE AG breach notification: an unknown number of Delaware residents affected

    source
  3. August 19, 2021
    Reported to regulator Regulator

    DE AG breach notification: an unknown number of Delaware residents affected

    source

Litigation

  • Possible litigation — multiple candidate dockets found, not yet resolved to a single case.
What a Delaware notice means

Governed by 6 Del. C. §12B-102. Notice to the Attorney General is required when a breach affects more than 500 Delaware residents.

Note: the count is Delaware residents only, not a total.

Delaware breach-notification register ↗

Confirmed incident

US-MA

Disclosed
March 31, 2021

Timeline

  1. March 31, 2021
    Reported to regulator Regulator

    MA AG breach notification: 1 Massachusetts residents affected

    source

Litigation

  • Possible litigation — multiple candidate dockets found, not yet resolved to a single case.
Confirmed incident

US-MA

Disclosed
October 14, 2020

Timeline

  1. October 14, 2020
    Reported to regulator Regulator

    MA AG breach notification: 3 Massachusetts residents affected

    source

Litigation

  • Possible litigation — multiple candidate dockets found, not yet resolved to a single case.

Related

Disclosed around the same time