Mercadien Data Breach
The 2025 Mercadien data breach affected 402,741 people according to the Indiana Attorney General's record.
Exposed Data Types
11- Names
- Physical addresses
- Dates of birth
- Driver's license numbers
- Government identification numbers
- Social security numbers
- Financial account information
- Usernames
- Passwords
- PIN codes
- Payment card information
About This Breach
Mercadien's official notice and a filing submitted to the New Hampshire Attorney General confirm unauthorized access to company systems and the potential involvement of personal information.
Mercadien provides accounting, tax, and advisory services. Because the incident may have involved information belonging to Mercadien's employees as well as organizations it served, some clients later issued their own notices; those notices concern the same Mercadien event.
How Did the Incident Occur?
According to the official filing submitted to the New Hampshire Attorney General, data was accessed between September 17 and October 9, 2025. Mercadien discovered the incident on November 7, 2025, reported it to law enforcement, and began an investigation with outside forensic specialists to determine its scope.
What Information Was Affected?
Mercadien's notice says the information potentially involved varies by person. It may include names, addresses, dates of birth, driver's license or other government identification numbers, Social Security numbers, and financial account information. For a more limited number of people, usernames and passwords, IRS PINs, or payment card information may also be involved.
What Did Mercadien Do?
Mercadien says it reset system passwords, conducted security scans across devices, and removed sensitive information from the affected system. The company also worked with law enforcement, legal counsel, and forensic specialists.
What Should Affected People Do?
Notice recipients should regularly review bank and payment-card activity, credit reports, and new accounts opened in their names. People whose password information was involved should replace reused passwords with unique ones and enable multi-factor authentication. Those whose Social Security or identification numbers were involved may also consider a fraud alert or credit freeze when appropriate.
Verification and editorial method
LeakData compares the incident name, date, affected-record count, and exposed data types with accessible sources. Unverified fields are not presented as facts, and records are updated when new evidence becomes available.
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