Most cheese subheadings carry TRQ treatment: a lower in-quota duty applies up to a specified annual volume, and a higher over-quota duty applies to additional quantities. Importers must track quota fill levels and secure quota allocations before shipment to avoid the higher rate.

Processed cheese — blended, emulsified, or heat-treated — is classified under 040630 (not grated or powdered). Natural ripened varieties such as Cheddar and Colby fall under 040690, while blue-veined types like Roquefort or Gorgonzola go to 040640. The distinction matters because each subheading carries its own TRQ parameters and duty rates.