In customs language a package is the unit the goods are presented in: carton, crate, pallet, drum. The declaration instructions in Annex 14 of the Turkish Customs Regulation ask for packages in two boxes, and both are expected to match the invoice and packing list.

BoxWhat goes in it
6 - Number of packagesTotal number of packages in the shipment
31 - Packages and description of goodsMarks and numbers of the packages, their count and kind; for unpacked goods the quantity or the word bulk; the normal commercial description of the goods

A transport container that comes back

When an insulated container leaves with the goods and returns empty, the description in box 31 should keep goods and container apart: the container's type and model, the count, the permanent numbers on it, and a note that it will be brought back. If five containers hold two hundred cartons, both figures are written separately and correctly; writing one in place of the other shows up as a count discrepancy on arrival.

On the way back the container can rely on Article 168 of the Turkish Customs Law: goods in free circulation that return within three years of export are exempted from import duties at the declarant's request. That requires showing the returning container is the one that left. The strongest trace is a number written the same way on the export declaration, on the delivery note and on the container body. Your customs broker decides which procedure and which fields apply to the transaction.

The number itself has to last. An adhesive label falls off or gets scraped away; a laser-marked number, a metal plate or permanent paint stays readable for the life of the container. Once the numbers are listed and handed to the broker, the same list serves every shipment, and in the inventory it also shows which container left with which shipment.