Mercadien PC Data Breach: What Information Was Exposed?

Mercadien PC Certified Public Accountants (“Mercadien”), a New Jersey accounting and advisory firm, has announced a data breach that may have exposed sensitive personal and financial information belonging to certain individuals. The firm discovered the incident on November 7, 2025, and launched an investigation.

What Happened in the Mercadien Data Breach?

Mercadien is based in Hamilton, New Jersey, and is known for its accounting and advisory services. After discovering the incident, the firm launched an investigation, involved law enforcement, and hired a national cybersecurity firm to assess and mitigate potential impacts.

Mercadien reported the breach to the Maine Attorney General and the Massachusetts Office of Consumer Affairs and Business Regulation in late December 2025. It also posted a data breach notice on its website.

What Information Was Exposed?

According to Mercadien’s notice, the information potentially affected may have included:

• Names
• Addresses
• Dates of birth
• Government ID numbers
• Social Security numbers
• Financial account details

For some individuals, the exposed information may also have included:

• Usernames and passwords
• IRS PIN numbers
• Payment card information

The information involved varied by individual, and not everyone had every data element exposed. Still, a combination like Social Security numbers, financial account details, and IRS PINs is especially sensitive, because it can be used for identity theft, tax fraud, and unauthorized account access.

What Should You Do After the Mercadien Data Breach?

If you received a notice from Mercadien, or believe your information may have been affected, consider taking these steps:

• Read any notice or letter you receive carefully, including any offer of credit monitoring or identity protection.
• Monitor your bank accounts, payment cards, and credit reports for activity you don’t recognize.
• Consider placing a fraud alert or credit freeze with the major credit bureaus.
• If your IRS PIN may have been exposed, watch for any sign of fraudulent tax filings.
• Change your passwords, especially if you reuse them across accounts, and turn on multi-factor authentication where available.
• Be cautious of unsolicited emails, texts, or calls asking for personal information.

Can You Take Legal Action After the Mercadien Data Breach?

If your personal information may have been exposed in the Mercadien data breach, you may have questions about your rights and potential legal options. Whether you can bring a claim depends on the circumstances of the incident and the harm you suffered.

Morgan & Morgan is investigating data breach incidents to help determine whether affected individuals may have legal options. See if you qualify for a case.