Delta Air Lines has been using a loophole to avoid paying what would likely amount to millions of dollars in tariffs on purchases of European planes.

The U.S.-based airline has acquired seven Airbus planes since President Donald Trump imposed new tariffs on various European imports in October 2019, under which large civil aircraft were initially subject to a 10% tariff, later raised to 15%. But Delta has successfully circumvented the fees by sending the planes overseas before bringing them to the U.S. — while other airlines appear to have been paying up.

Marketplace’s Kai Ryssdal spoke to journalist Siddharth Philip, who reported the story for Bloomberg. He said Delta’s workaround is 100% legal.

“Based on the list prices of the aircraft, it could have saved as much as $270 million, although airlines don’t actually pay the list price for planes, and so the true savings could be much smaller than that,” Philip said.

Click the audio player above to hear the interview.