The April 2 modifications to Section 232 tariffs on steel, aluminum, and copper now apply duties to the full import value rather than solely to metal content — and USTR's two active Section 301 investigations threaten to layer additional duties on top, creating a "tariff stacking" scenario that breaks assumptions in most duty calculation pipelines.
Caterpillar flagged the compliance engineering problem directly in its USTR filing: "Stacking additional Section 301 tariffs on these same products would further exacerbate cost pressures, disrupt supply chains, undermine US export competitiveness and fail to address the specific practices Section 301 is intended to address." For teams maintaining rate caches, this means any HTS code subject to both Section 232 and potential Section 301 duties now requires conditional logic that accounts for the April 2 full-value assessment basis before applying any future 301 rate.
USTR has launched two Section 301 investigations targeting structural excess capacity and forced labor practices. India is among the countries facing probes on both fronts — charges the Indian government has dismissed. Indian Pharmaceutical Alliance stated in its filing that "India does not maintain structural excess capacity in this sector," while CII urged USTR to consider "the broader strategic partnership between the US and India" and its role in supply chain diversification away from non-market economies.
The stacking risk extends across multiple sectors. Dell, Ford, Delta Air Lines, Jockey International, and the US Chamber of Commerce have all filed comments opposing additional Section 301 duties. Ford specifically requested a credit system to offset Section 232 tariffs against any Section 301 duties — a workaround that would require entirely new calculation logic if implemented. The Cheese Importers Association of America warned that 301 duties on EU and Swiss dairy products would compound existing cost pressures on American consumers.
US inflation rose to 3.3% in March amid higher tariff costs, and companies are citing production economics as a barrier to reshoring. Jockey International argued that "attempts to mass reshore apparel manufacturing jobs through section 301 tariffs is not a realistic outcome and will only create inflationary pressures." Meanwhile, toy manufacturers, solar energy producers, and industrial equipment makers have all petitioned against tariffs on goods already subject to Section 232.
The compliance engineering challenge is compounded by the lack of clarity on which HTS codes will ultimately face Section 301 duties. With investigations still underway and no final determinations issued, teams must track both the structural capacity probe and the forced labor probe across multiple product categories — from civil aircraft and engines (flagged by Delta) to steel-using manufactured goods (flagged by Caterpillar and Cummins).
Indian entities including Reliance Industries, Adani Group's Mundra Solar, Indian Solar Manufacturers Association, ACMA, and textile industry bodies have submitted responses emphasizing that India's constitution prohibits forced labor. These filings will factor into USTR's determination, but the timeline for final action remains uncertain — meaning rate tables for affected HTS codes cannot be considered stable.