US wheat is traded in distinct classes — including hard red winter, hard red spring, durum, soft red winter, and white wheat — each with different protein content, gluten strength, and milling characteristics. While HTS classification may group some classes together, commercial contracts are class-specific, and mislabeling wheat class on documentation can create both contractual and regulatory complications.

USDA APHIS restricts or conditions wheat imports from origins where Karnal bunt (Tilletia indica) or other regulated wheat pathogens are present. Affected shipments may require phytosanitary certificates with specific declarations, treatment, or testing before entry is permitted. Importers should check current APHIS import requirements for the specific origin country before contracting.