Keep postage low by sending flat, flexible, paper envelopes only—no boxes, no rigid or padded envelopes.
Postal Categories
Letters (smaller flexible envelopes)
Flats (larger flexible envelopes)
Packages (rigid envelopes or boxes)
Letters and Flats require significantly less postage than Packages, especially for international deliveries.
Letters and Flats are distinguished from Packages by their combined flexibility and uniform thickness.
Letters and flats are distinguished from one another by their dimensions:
Letter envelopes must be rectangular and made of paper, and can be a maximum of 11-1/2″ (292mm) long x 6-1/8″ (155mm) high, with a uniform thickness of up to 1/4″ (6mm). Flats (large envelopes) can be a maximum of 15″ (381mm) long and 12″ (305mm) high, with a uniform thickness of up to 3/4″ (19mm).
The maximum weight for Letters is 3.5 oz (100g); the maximum weight for Flats is 13 oz (368g).
In addition to boxes, rigid envelopes are considered packages; flexible, lumpy envelopes are too, in some cases. NOTE: Flat, flexible envelopes marked DO NOT BEND may also be considered packages.
International Package Delivery
International PACKAGE delivery originating in the USA is prohibitively expensive and prone to Customs complications and delays. Sending LETTERS and FLATS requires no Customs form and is an affordable alternative to package delivery. U.S. American participation in international groups will require voluntary adoption of material limitations associated with sending ‘Letters’ and ‘Flats.’
Please be in touch with any questions or comments. [marty@berkeleycommonplace.com]