U.S. Customs and Border Protection (“CBP”) has a dedicated page to the “First Sale” rule, which is here. In simple terms, “First Sale” is declaration technique that emphasized declaration to CBP based on original factory prices, instead of middle person or agent company prices. It is safe to say that “first sale” is not embraced with enthusiasm in some CBP circles, and has a history of litigation, with most famous case being Nissho Iwai v. U.S., 982 F.2d 505 (CAFC, 1992). But the rule is available, and CBP dedicated webpage is a friendly reminder to the trade community about its use.