A former senior executive at WPP’s media division has filed a lawsuit in New York’s state Supreme Court alleging the global advertising holding company fired him after he raised internal concerns about rebate and accounting practices.

According to the complaint filed Nov. 11, Richard Foster – who previously served as CEO of what is now WPP Media – claims that between 2019 and 2024 WPP and its media arm retained billions of dollars in rebates and incentive payments from media owners rather than passing those discounts on to clients. The filing alleges these practices generated between USD$1.5 billion and $2 billion in additional profit for the company during that period.

The complaint states that Foster reported his concerns to WPP’s legal and compliance departments, asserting that certain rebate and incentive arrangements with media vendors were improper and that related accounting practices misrepresented how those rebates were handled. Foster alleges he was subsequently terminated in retaliation for making those reports.

While the lawsuit centres on U.S. operations, the claims touch on long-standing global questions about transparency in media trading, particularly around “agency volume bonuses” and how they are disclosed to clients. The lawsuit alleges these practices ultimately turned the agency into a “non-disclosed profit centre.”

For Canadian advertisers and agencies operating within global holding-company networks, the complaint highlights how global trading and incentive structures can affect local media buying and pricing. The filing may prompt renewed scrutiny of audit rights, contract language and how value-added incentives are reported to clients.

WPP had not yet filed a response as of publication, and none of the allegations have been proven in court.

In a statement provided to media outlets, including Business Insider and the Los Angeles Times, WPP said it is aware of the lawsuit and will defend the allegations vigorously.

Media in Canada has reached out to WPP for comment.