Every controller knows the sentence that ends careers: “We booked that as revenue.” For a year, Washington booked tariff collections as revenue. Then the Supreme Court ruled 6-3 in Learning Resources v. Trump that the emergency law behind tariffs never authorized them. Now the money is going back out the door.

The scale is hard to overstate. Customs and Border Protection says it assessed about $166 billion in these duties between February 2025 and February 2026, paid by more than 330,000 importers. As of Sept. 11, 2026, it had accepted $134.7 billion in refund claims and sent roughly $122 billion, interest included, to the Treasury for payment. In May alone, Treasury refunded nearly $22 billion, about what it collected in tariffs that month. The refunds erased the revenue. A stream of money the administration counted on netted to roughly zero for the month, and almost nobody noticed because gross collections get the press release while net receipts get a footnote.