A diplomatic courier is a government official export and import trained and credentialed by the Secretary of State to accompany classified materials across international borders, Duty and Tax is exemption 

• Embassies, legations, consular posts, and the foreign office of any government

• The headquarters or any other office of a public international organization and its regional offices in the United States or in a foreign country.

• The foreign office of any country with full membership in a public international organization and its mission to that organization.

The following documents must be submitted to process goods with diplomatic immunity.

•  Letter from Ministry of Foreign Affairs

•   Letter from the Diplomatic Mission

•  Documents required to process import/export