Langwasser & Co CPAs Breach Exposes Social Security Numbers

Langwasser & Company CPAs, a full-service accounting firm based in Upland, California, experienced a data breach in May 2026.

Langwasser & Company CPAs offers a broad range of services that require the handling of sensitive personal and financial records. These services include tax preparation, estate and gift planning, IRS representation, financial planning, business consulting and litigation support.

On May 5, 2026, Langwasser & Company CPAs discovered that a number of unauthorized tax returns were filed. The types of personal information exposed in this breach included Social Security numbers and financial account information.

The breach was reported to the attorneys general of California and Massachusetts.

Langwasser & Company CPAs' response to the breach

The firm is offering credit monitoring services to affected individuals through Experian IdentityWorks. The details on how long the services last, how to enroll and specific deadlines are included in each individuals' notification letter.

Affected individuals who have questions about the breach can reach the firm at the dedicated line listed in their notification letter, available Monday through Friday from 6:00 a.m. to 3:30 p.m. Pacific time. The firm listed its mailing address for correspondence related to this incident as 99 E C St. 100, Upland, CA 91786.

Individuals who received a notification letter from the firm should take prompt action to safeguard their credit and financial accounts.