A Costco customer in Illinois has filed a proposed class-action lawsuit against the retail giant seeking refunds related to tariffs imposed during the Trump administration. The lawsuit comes after the Supreme Court struck down a significant portion of the former president's import taxes last month.

The legal action seeks to force Costco to pass along to customers any tariff refunds the company receives from the U.S. government. The plaintiff argues that the retailer should not be allowed to keep refunds for tariffs that were ultimately passed on to consumers through higher prices.

The lawsuit describes its goal as preventing "double recovery" by Costco, contending that the corporation should share tariff refunds with the customers who bore the cost of the import taxes through increased merchandise prices.

The case highlights broader complexities surrounding potential tariff refunds, with an estimated $166 billion in refunds potentially at stake across various industries and retailers. The Supreme Court's decision to overturn much of the Trump administration's tariff structure has created uncertainty about how refunds will be distributed.

If certified as a class action, the lawsuit could encompass numerous Costco customers who purchased goods during the period when the now-invalidated tariffs were in effect. The retailer has not yet publicly responded to the legal challenge.