Banknotes that are legal tender or were issued as legal tender — whether current or withdrawn from circulation — are generally classified under 4907 when unused or uncirculated. Heavily circulated or cancelled notes traded purely as collectibles may shift to the chapter covering collectors' pieces, depending on their condition and the context of the transaction. A binding ruling is advisable for large-volume numismatic imports.

Importation of currency and monetary instruments above certain thresholds requires filing a FinCEN Form 105 (Report of International Transportation of Currency or Monetary Instruments) with CBP. Additionally, CBP and the Department of the Treasury have authority over the importation of foreign currency and negotiable instruments. Importers should consult a licensed customs broker and legal counsel familiar with currency reporting requirements before importing significant quantities.