Williams Accountancy Data Breach Exposes Client PII

Williams Accountancy Corporation, a California-based accounting firm, recently experienced a data breach that exposed sensitive personal information of its clients.

According to a notice filed with the California Attorney General, the breach occurred over two days, Dec. 25 and Dec. 26, 2025. An unauthorized third party gained access to the company’s network and acquired files containing client data.

The company discovered the incident on Dec. 30, 2025, and began an internal investigation, engaging a forensic security firm to assist in containment and remediation. The review of affected files concluded on Feb. 5, 2026, confirming that the exposed data included highly sensitive financial and identification information.

The forensic investigation determined that the attacker accessed certain systems and exfiltrated files containing personally identifiable information (PII), including names, dates of birth, Social Security numbers and bank account numbers.

Williams Accountancy Corporation's response

For those affected, Williams Accountancy is offering a complimentary membership to Experian IdentityWorks Credit 3B. This service provides credit monitoring from all three major credit bureaus, identity restoration support, and up to $1 million in identity theft insurance.

Affected individuals are encouraged to enroll in this service and to remain vigilant by monitoring their financial accounts and credit reports for suspicious activity.

Additionally, the company recommends placing fraud alerts or credit freezes with the major credit bureaus as an extra precaution.

Contact information for Equifax, Experian and TransUnion, as well as guidance from the Federal Trade Commission, is provided in the notice to consumers, which will be available at the bottom of this page in PDF format.