Mercadien CPAs Data Breach Lawsuit Investigation
Received a September 2026 breach notice from Mercadien CPAs?
Dapeer Law, P.A. is investigating a potential class action against Mercadien CPAs, a Princeton, New Jersey accounting and advisory firm, on behalf of individuals whose personal information may have been involved in the data security incident the firm detected in November 2025.
Who may qualify
You may be eligible to participate in a class action if any of the following applies:
- You received a data breach notification letter from Mercadien CPAs dated September 2026.
- Your letter offered enrollment in free Experian IdentityWorks credit monitoring.
- Your letter states that your information was in files Mercadien CPAs received in connection with an advisory services engagement.
- No proof of harm required to consult with counsel. You do not need to have already suffered identity theft to explore your legal options.
- Excluded: individuals who did not receive a breach notice and whose information was not involved in the incident.
Not sure if you qualify?
Send us your notice, we'll confirm your eligibility at no cost.
What happened
Mercadien CPAs states in its notice letter that it provides accounting and advisory services to financial institutions and obtained individuals' information while providing these services. The firm detected a data security incident on November 7, 2025. According to the letter, a third-party investigation confirmed that an unauthorized third party accessed files from the firm's systems. The letter does not state when the unauthorized access began or ended, but the Indiana Attorney General's breach report lists the breach as occurring on September 17, 2025.
Mercadien CPAs then completed a data analysis of the files involved. On August 13, 2026, the firm determined that the files included information it received from another organization, named in each individual letter, related to an advisory services engagement, which included individuals' names and Social Security numbers. The letter states that the incident occurred on the Mercadien CPAs network and did not impact the systems and files of the recipient's financial institution. The notice posted by the California Attorney General lists name and Social Security number as the information involved.
The sample letter is dated September 15, 2026, more than ten months after the incident was detected. It offers free credit monitoring through Experian IdentityWorks and states that approximately 436 Rhode Island residents may be impacted. Mercadien CPAs reported 402,760 total affected individuals to the Indiana Attorney General, and the Texas Attorney General lists 5,219 Texas residents affected. Whether the firm's security practices met legal standards, and whether the time between detection and notice caused additional harm, are among the issues being evaluated.
What to do if you received a letter
Keep your notice letter
Do not discard it. Your letter contains your Experian IdentityWorks activation code and is important evidence if you decide to participate in a lawsuit.
Enroll in the free Experian IdentityWorks monitoring
Enroll at the Experian IdentityWorks site listed in your letter using the activation code printed there. The sample letter sets an enrollment deadline of December 31, 2026, so check your own letter for your deadline. Accepting this benefit does not waive your right to pursue legal action.
Place a fraud alert or credit freeze
Contact Equifax, Experian, and TransUnion to place a fraud alert or freeze on your file. Request a free weekly credit report from AnnualCreditReport.com, and use the FTC's IdentityTheft.gov recovery guide.
Speak with a data breach attorney
Consultations with Dapeer Law are free and confidential. We'll review your notice, explain your options, and advise whether you may be eligible to join a class action.
Submit your notice for a free review
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Breach timeline
Compensation you may be entitled to
Out-of-pocket expenses
Credit freezes, identity restoration services, and other costs incurred responding to the breach.
Time spent monitoring
Hours spent reviewing accounts, disputing fraudulent charges, and dealing with identity theft issues.
Identity theft & fraud losses
Unreimbursed funds stolen from accounts, unauthorized credit lines, or tax refund fraud tied to the breach.
Statutory damages
Certain state data breach and consumer protection statutes provide for fixed damages regardless of actual loss.
Injunctive relief
Court orders requiring the firm to implement stronger data security practices for the personal information it receives in its accounting and advisory work.
Compensation categories depend on applicable state law, the types of data exposed, and documented losses. No recovery is guaranteed.
Common questions
I received a data breach letter from Mercadien CPAs. What should I do? +
Keep the letter, enroll in the free Experian IdentityWorks credit monitoring using the activation code in your letter before your enrollment deadline (December 31, 2026 in the sample letter), consider placing a fraud alert or credit freeze, and contact a data breach attorney for a free consultation. Because the letter states that your Social Security number was in the files involved, review your credit reports regularly. Accepting credit monitoring does not waive your right to sue.
Am I eligible to join a class action against Mercadien CPAs? +
If you received a breach notice letter from Mercadien CPAs about this incident, you are likely eligible for a free case evaluation. Eligibility depends on your state of residence, the categories of your data that were involved, and any losses you have suffered. Dapeer Law will review your notice at no cost.
How much money could I receive from a class action lawsuit? +
Data breach class action recoveries vary significantly. Settlements typically range from a few hundred dollars for basic out-of-pocket losses to several thousand dollars for documented identity theft, with class size, damages, and negotiation all affecting the final amount. No payout is guaranteed, and this investigation has not yet resulted in a settlement.
What personal information was exposed in the breach? +
The sample letter states that the files involved included information Mercadien CPAs received in connection with an advisory services engagement, which included your name and Social Security number. The notice posted by the California Attorney General lists name and Social Security number. The letter also states that the incident occurred on the Mercadien CPAs network and did not impact the systems and files of the recipient's financial institution. Check your individual letter for the categories of your data that were involved.
Did Mercadien CPAs offer free credit monitoring? +
Yes. The letter offers free credit monitoring through Experian IdentityWorks, which it describes as including an Experian credit report at signup, monitoring of your Experian credit file, identity restoration support, and identity theft insurance. The sample letter does not show the number of months of coverage. The sample letter sets an enrollment deadline of December 31, 2026, so check your own letter for your deadline. Enrollment does not waive your right to pursue a claim.
How many people were affected by the Mercadien CPAs breach? +
Mercadien CPAs reported 402,760 total affected individuals to the Indiana Attorney General. The Texas Attorney General lists 5,219 Texas residents, and the sample notice letter states that approximately 436 Rhode Island residents may be impacted. This page will be updated as additional information becomes available.
Is there a deadline to take legal action? +
Yes. Statutes of limitations for data breach claims vary by state and legal theory, typically ranging from one to six years. Waiting can permanently bar your claim. Contact us as soon as possible for a free evaluation.
How do I get a copy of the official breach notice? +
A sample of the notice letter is available through the California Attorney General's data breach notification site (linked in Sources below). If you received a letter but no longer have it, Dapeer Law can assist you in obtaining a copy during your free consultation.
Sources & references
- Official breach notice filing · California Attorney General, Mercadien, P.C. CPAs Sample Notice Letter
- Secondary regulator report · Indiana Attorney General, 2026 Data Breach Year-to-Date Report (Mercadien PC Certified Public Accountants)
- Secondary regulator posting · Texas Attorney General, Data Security Breach Reports (posted October 13, 2026)
- Credit bureau freezes · Equifax · Experian · TransUnion
- Free weekly credit reports · AnnualCreditReport.com
- Identity theft recovery guide · FTC IdentityTheft.gov
Don't let the deadline decide for you. Submit your claim today.
You only have a limited window to act. Our team will review your notice, explain your options, and tell you whether you may be eligible to recover compensation, at no cost to you.