Suffolk Credit Union Data Breach Class Action Investigation

Account records belonging to members of Suffolk Credit Union were accessed without authorization after a breach at a former accounting vendor. If you received a data breach notification letter from Suffolk Credit Union / Mercadien, our data breach lawyers want to hear from you.

What Happened?

According to a notice filed with the California AG Office, member information held by Suffolk Credit Union was exposed in a data breach at Mercadien, P.C., CPAs, a former service provider to the credit union. The breach occurred on September 17, 2025. Information exposed in the breach reportedly included full names, mailing addresses, dates of birth, government identification numbers, Social Security numbers, and financial account information. Affected individuals were notified by mail beginning in September 2026. The incident was limited to the vendor's systems and did not involve Suffolk Credit Union computer systems.

If you are a member who are a member of Suffolk Credit Union / Mercadien, you may be entitled to compensation. Fill out the form below to see if you qualify.

Steps To Take If You Were Affected

1. Monitor your credit reports and financial accounts for suspicious activity
2. Consider placing a fraud alert or credit freeze with all three major credit bureaus
3. Be alert to phishing emails or calls referencing the breach
4. Change passwords on any affected accounts and enable two-factor authentication
5. Keep a copy of your data breach notification letter for your records