All articles that are nonmailable in domestic mail are nonmailable in international mail. See DMM 601 and Publication 52, Hazardous, Restricted, and Perishable Mail.
Many articles that are mailable in domestic mail are nonmailable in international mail. See chapter 6 of Publication 52 and “Prohibitions and Restrictions” in the Individual Country Listings.
Information on articles that are prohibited or restricted to individual countries appears under “Prohibitions and Restrictions” in the Individual Country Listings. These prohibitions and restrictions are based on information furnished by the countries concerned. Customers should inquire at the Post Office facility about specific prohibitions or restrictions.
Articles that are prohibited by the destination country are nonmailable. For mail known to contain articles restricted by the destination country, the sender must be informed of the restrictions and advised that the articles are subject to the import requirements of that country.
A country may return or seize mail containing articles prohibited or restricted within that country, whether or not notice of such prohibition or restriction has been provided to or published by the Postal Service.
The Postal Service does not maintain or provide information concerning the assessment of customs duty in other countries. Postal Service employees must not attempt to inform customers whether articles (gifts or commercial shipments) will be subject to customs duty. Postal Service employees may suggest to customers, however, that they inform the addressees in advance of the articles they intend to mail. Addressees can then obtain information from their local customs authorities. No provision is made for prepayment of customs duty on mail addressed for delivery in foreign countries.
If duties or taxes are assessed, most countries will collect from the recipient a customs clearance and delivery fee, in addition to the duties and taxes. This fee is authorized by international postal agreements to reimburse the delivery service for the costs it incurs in clearing the items through customs and collecting duties at the time of delivery. The duties, taxes, and fee, if applicable, are not included in the postage paid by the mailer.
Regardless of any statement in this manual or the statement of any employee of the United States Postal Service, the burden rests with the mailer to ensure compliance with domestic, international, and individual country rules and regulations for mailability.
Parcels of articles or goods must meet the requirements of DMM 601. The size and weight limits for each of several grades of fiberboard boxes are as specified for difficult loads in DMM 601. Reinforce boxes in each of two directions around the package.
Each mailer must meet the following special packaging requirements when mailing any of the following articles (see DMM 601):
- Fragile articles, such as glass, must be cushioned as required to dissipate shock and pressure forces over as much of the surface of the item as possible.
- Liquids must be packaged as required.
- Package fatty substances that do not easily liquefy, such as ointments, soft soap, resins, etc., as well as silkworm eggs, in an interior container (box, cloth, or plastic bag) and place them in an outer shipping container of minimum 275–grade test strength.
- Enclose dry, powdered dyes, such as aniline, in sift–proof, sturdy tin or plastic boxes in an outer sift–proof shipping container. This container must have a minimum 275–grade test strength fiberboard or equivalent.