Shipping carriers have different address format requirements when shipping to United States territories and possessions. Some carriers may also require customs paperwork. You’ll be prompted to complete it when necessary (see Generating Customs Forms with Shippo).
USPS
The USPS requires the recipient address to list United States in the Country field and the two-letter abbreviation for the territory or possession in the State field (see below). This will allow you to see domestic shipping service levels with the USPS.
DHL Express, UPS, and FedEx
Please use the territory or possession name in the Country field to generate rates with these carriers.
Abbreviations for U.S. Territories and Possessions:
AS—American Samoa (includes Manua Island, Swain’s Island, and Tutila Island)
GU—Guam
UM—U.S. Minor Outlying Islands
MP—Commonwealth of the Northern Mariana Islands (includes Rota Island, Saipan Island, and Tinian Island)
PR—Commonwealth of Puerto Rico
VI—U.S. Virgin Islands (includes St. Croix Island, St. John Island, and St. Thomas Island)
Abbreviations for Freely Associated States:
MH—Republic of the Marshall Islands
FM—Federated States of Micronesia
PW—Republic of Palau