If you disagree with a decision made by U.S. Customs and Border Protection or want to correct information previously entered on entry documents, you have three options.
The options available depend on whether or not the entry or entries have liquidated, meaning have been closed out by CBP. Once liquidation has occurred, the only option available is to file a Protest. 19 U.S.C 1514 - Protest Against Decisions of Customs Service provides the legal vehicle for importers and interested parties to administratively contest CBP decisions related to imported merchandise.
Within 180 days of liquidation, the importer, their broker, or attorney can contest CBP decisions relating to imported merchandise with a protest under section 514 of the Tariff Act of 1930. Protests and petitions are generally filed on CBP Form 19. This form has instructions on what is needed to file a protest. However, there is no statutory requirement that a protest or petition be filed on CBP Form 19.
Any document received which can be construed to contest a decision and is signed by the party of interest should be treated as a protest.