Which document is required for customs purposes when sending international packages?

The correct response highlights the importance of the customs declaration when sending international packages. A customs declaration is a document that provides essential information about the contents of the package, including its value, description, and purpose. This document is crucial for customs authorities to assess any applicable duties and taxes, determine compliance with trade regulations, and ensure that the shipment adheres to the laws of both the sending and receiving countries.

The customs declaration serves as a legal statement regarding the contents of the package, which is necessary for the clearance process at international borders. It helps ensure that packages are processed efficiently and reduces the likelihood of delays.

While other documents like a pro forma invoice or a shipping label may be useful in the shipping process, they do not fulfill the specific requirements established by customs authorities. An export license might be necessary for specific goods but is not a blanket requirement for all international shipments. Hence, the customs declaration stands out as the definitive document needed for customs purposes.