(a) Entries at one port. If by reason of accident or short shipment a portion of the quantity covered by one invoice fails to arrive, or if for any other reason only a portion of the quantity covered by one invoice is entered under one entry, a photocopy of the commercial invoice used in connection with the first entry, covering the quantity to be entered under another entry, may be used in connection with the subsequent entry of any portion of the merchandise not cleared under the first entry.

(b) Entries from foreign-trade zone at one port. A photocopy of the invoice filed with the first entry for consumption from a foreign-trade zone of a portion of the merchandise shown on the invoice will not be required for any subsequent entry for consumption from that zone at the same port of a portion of any merchandise covered by such invoice, if a pro forma invoice is filed and identifies the entry first made and the invoice then filed.

(c) Entries at different ports. When portions of a single shipment requiring a commercial invoice are entered at different ports, the importer may submit to the port director where the original invoice or latest photocopy of the original invoice is on file, two photocopies of the latest of such invoices to be certified as to merchandise previously received, and the official seal affixed thereto.

(d) Pro forma invoice. In a case in which a portion of the shipment is entered at the first port on a pro forma invoice, an entry at a subsequent port may be made by means of a new pro forma invoice which may cover only the merchandise then entered.

(e) Photocopy to satisfy bond for invoice. A properly certified photocopy of a commercial invoice presented within 6 months after the date of entry may be accepted to cancel the charges against the bond given for the production of the commercial invoice.