BATON ROUGE, La. (AP) — The head of a powerful Louisiana business lobbying group is urging companies who operate in multiple states to pursue refunds for taxes paid under a 2015 law declared unconstitutional.

Stephen Waguespack, president of the Louisiana Association of Business and Industry, said those companies should contact tax professionals to determine ways to seek the recovery.

In his weekly column, Waguespack wrote: “Taxpayers need to take steps now to protect themselves.”

The Louisiana Supreme Court this month threw out the three-year-old law that scaled back an income tax break the state allows for taxes paid to other states.

The change was expected to raise millions for the state.

But Revenue Secretary Kimberly Robinson said Louisiana only will have to return $23,000 that the taxpayers who filed the lawsuit paid under protest.