Washington’s Sanford Wittels & Heisler has filed its fourth wage-and-hour class action in California within the past three months after expanding its San Francisco office.

On Aug. 19, the firm filed a $100 million class action against United Parcel Service Inc. on behalf of at least 5,000 account managers nationwide, including 1,500 in California, who allege that they routinely have been denied overtime compensation.