Hallo Brigi
Hab mal schnell bei USPostal geschau und das hier gefunden:
Letter-post items weighing 16 ounces or more, and all potentially dutiable items regardless of their weight, require the applicable customs forms.
A customs form is not required on the following categories of mail:
Non-dutiable letter-post items that weigh less than 16 ounces.
Non-dutiable letter-post items that weigh 16 ounces or more when they are tendered by a known mailer (tenders volume mailings through a Business Mail Entry Unit or other bulk mail acceptance location; completes a statement of mailing at the time of entry; pays postage through an advance deposit account; and utilizes a permit imprint as an indication of postage payment. International Surface Air Lift and International Priority Airmail customers and federal, state, and local government entities are considered to be "known mailers" for this purpose).
Wenn die Prospekte mehr als 16 Unzen gewogen haben, dann ist der Zettel zwingend. Hab aber letzte Woche auch Prospekte bekommen die nicht so schwer waren und trotzdem die Zolldeklaration draufhatten. Wie das von D nach USA ist findest du ev. auf der Homepage der Deutschen Post.
Eisi