CITES documentation is required when an instrument contains parts made from species listed under the Convention on International Trade in Endangered Species — most commonly Brazilian rosewood (Dalbergia nigra) in guitar fretboards or backs, or certain ebony species in fingerboards. The US Fish & Wildlife Service enforces CITES at the port of entry, and instruments lacking proper permits can be detained or seized regardless of their commercial value.

Customs value is based on the transaction value of the imported merchandise, not on a grade designation. However, grade and specification documentation — materials used, country of manufacture, and whether the instrument is handcrafted — can affect both the applicable HTS subheading and the dutiable value if assists (such as tooling or design provided by the US buyer) are involved. Accurate commercial invoices specifying materials and construction method help prevent valuation disputes.