
The measure itself took effect on July **. According to the US Trade Representative (USTR), the action followed a determination that ** economies had failed to adequately enforce prohibitions on goods produced with forced labour. The Federal Register notice published on July ** formally implemented the new duties across most tariff lines. US Customs and Border Protection (CBP), through CSMS #********, clarified the limited exemption: cargo qualified only if it had been loaded on its final ocean voyage before July ** and was entered for consumption before July **. Shipments arriving by air, truck, or rail were never eligible, and no subsequent guidance extended the filing deadline.
The cost impact importers cannot reverse
For affected importers, the additional duty represents a permanent increase in landed cost rather than a temporary surcharge. Unlike the IEEPA tariffs invalidated by the US Supreme Court in February ****, these Section *** duties have no established refund mechanism. The duty becomes payable when goods enter the United States. As a result, even cargo arriving before the deadline became fully liable if customs entry was filed after the exemption period expired. Customs brokers consistently described the deadline as a documentation challenge rather than a shipping challenge.
The new duties apply in addition to existing most-favoured-nation (MFN) tariff rates and previous China Section *** duties. They do not stack with Section *** tariffs. For a typical apparel container, the incremental duty can amount to tens of thousands of dollars, creating an immediate cash-flow impact for importers.

