The American Alliance for Solar Manufacturing Trade Committee sent a letter to the US International Trade Commission urging the agency to make a final determination on anti-dumping and countervailing duty (AD/CVD) tariffs by June 2 to ensure tariffs are in effect before a window of duty-free imports opens.

The letter warned that “significant quantities” of solar cells and modules are “being held in bonded warehouses or otherwise prepared to enter the United States” duty-free.

Solar products shipped from Vietnam, Malaysia, Cambodia and Vietnam, four nations responsible for as much as 80% of U.S. solar module supply, are currently subject to tariffs under a preliminary finding of AD/CVD violation. The preliminary tariff rates went into effect on December 4, 2024 and apply until June 1, 2025.

If the US International Trade Commission on June 2 announces a determination that solar product imports from the four countries have materially harmed the US domestic industry, Commerce’s final tariff rates will go into effect a couple of weeks later.

Commerce has already set its final AD/CVD tariff rates, which came in higher-than-expected and are as high as 81% to 3,403% of the cost of shipped goods.

The US International Trade Commission announced this week it would make a final determination by June 30. However, if the agency does not make a final determination of material harm by June 2 goods could be imported into the US duty-free for a brief period.

“Petitioner has reason to believe that there are significant quantities of [crystalline solar PV] products from these countries that are ready to be withdrawn from warehouses and surge into the US market,” said the letter, submitted by law firm Wiley Rein on behalf of the trade committee.