US tariff structures favour cotton over competing fibres, yet cotton has lost market share in six of eight tracked apparel categories, according to a Fibre2Fashion analysis that exposes a gap between trade policy and on-the-ground sourcing outcomes.

The headline finding — that cotton underperforms in 75 percent of categories reviewed — sits uneasily with a US tariff schedule that, on paper, protects domestic and imported cotton against synthetic alternatives. For brand sourcing teams weighing fibre mix and country of origin, the disconnect raises immediate questions about whether tariff relief is reaching the cotton segment or being absorbed before the buy decision is taken.

For procurement leads, the data point reframes a long-running assumption: that favourable tariff treatment translates into competitive positioning at the finished-goods level. The fact that cotton has ceded ground in three-quarters of the categories under review suggests that price advantage at the border is not flowing through to the buy side in most segments. Sourcing managers tracking landed-cost models will need to identify where in the chain the differential is being eroded — whether at yarn, fabric, or finished-garment stage.

What does the gap between tariff and market share mean for sourcing?

The category-level granularity matters here. With cotton losing share in six of eight categories, the two segments where cotton has held or grown position become the analytical anchor. Identifying those segments, the price points at which cotton competes, and the certification or sustainability claims attached to those wins is now the priority question for fibre strategists.

Sourcing priorities to interrogate the finding:

• Map the two winning cotton categories against current sourcing volumes to size exposure
• Revisit supplier contracts where cotton content has declined, checking whether mills are substituting synthetics
• Audit finished-goods HTS classifications to confirm the tariff advantage is being captured at import
• Track landed-cost deltas between cotton-rich and synthetic-rich SKUs in the six losing categories

The result also carries implications for synthetic fibre producers, who appear to be winning in six of eight segments despite a tariff schedule tilted against them. For polyester, nylon and rayon suppliers, the data suggests their cost structures and supply-chain flexibility are out-competing the tariff gap at the finished-goods level. That dynamic should inform any forward hedging on cotton contracts, particularly into the back half of 2026 where order books are still being finalised.

What should compliance and fibre buyers watch next?

Compliance teams should re-examine the rules of origin attached to cotton imports. If the tariff benefit is conditional on US origin or specific processing steps, the share loss may reflect compliance friction rather than commercial preference. Resolving that distinction is essential before rebalancing the fibre mix or revising supplier scorecards. Until the category-by-category breakdown — which six segments cotton is losing, which two it is retaining, and at what price tier — is itemised, the working reading is that US tariff structure is a necessary but not sufficient condition for cotton's commercial recovery, and that mills and brand sourcing partners will absorb the cost-translation work that the policy alone is not doing.