USDA APHIS requires a phytosanitary certificate from the exporting country's national plant protection organization, and certain origins or seed types may require an APHIS import permit. The Federal Seed Act additionally requires that seed lots be labeled with germination percentage, purity, and variety name. Importers should confirm permit requirements with APHIS well in advance of shipment. Classification and admissibility are complex; consult a licensed customs broker or APHIS before importing.

Seed corn classifies separately from feed or processing corn because it is specifically prepared and certified for planting. The distinction rests on the importer's declared end use and accompanying seed certification documents. Misclassifying commodity corn as seed corn — or vice versa — can result in penalty and seizure, so documentation must clearly establish the planting-grade status of the shipment.