To write an FPO address, format it like a regular U.S. address but replace the city with “FPO,” replace the state with one of three military codes (AE, AP, or AA), and use the military ZIP Code the service member gives you. The recipient’s name and rank go on the first line, the unit and box number or the ship’s name and hull number on the second, and “FPO” plus the code and ZIP on the third. Do not write the foreign country or city anywhere on the envelope. USPS treats the piece as domestic mail and charges domestic postage.1United States Postal Service. Military and Diplomatic Mail
The Line-by-Line Format
Every FPO address uses three lines. Print them in block letters, in this order:
Line 1: full name with rank.
Line 2: unit and box number, or ship name and hull number.
Line 3: FPO, the two-letter military code, and the ZIP.
For a sailor assigned to a shore unit:
PO2 JANE DOE
UNIT 100535 BOX 4290
FPO AP 96373-1234
For someone aboard a ship, the second line names the vessel and its hull number:
SGT JOHN SMITH
USS ABRAHAM LINCOLN (CVN-72)
FPO AP 96616-2872
The name and rank matter because military mail clerks at the destination sort by them; a package addressed vaguely can sit unclaimed. The unit or ship line tells the clerks where the person is assigned once the mail reaches the installation. Use the full nine-digit ZIP when you have it, since it speeds sorting.1United States Postal Service. Military and Diplomatic Mail
FPO stands for Fleet Post Office and covers the Navy, Marine Corps, and Coast Guard.2Defense Technical Information Center. Military Post Office Location List Army and Air Force personnel use APO addresses, and State Department personnel use DPO. The line-by-line format is identical; only the three letters at the start of line three change.
Choosing the Right Military State Code
The two-letter code in place of a state abbreviation tells USPS which military mail gateway handles the piece.3National Finance Center. State, U.S. Territory, and Overseas Military Abbreviations Table There are three:
- AE, Armed Forces Europe, covers Europe, the Middle East, Africa, and Canada.
- AP, Armed Forces Pacific, covers Asia, the Pacific Islands, and surrounding waters.
- AA, Armed Forces Americas, covers Central America, South America, and the Caribbean. It does not include Canada, which routes through AE.
You do not have to work out the code yourself. The service member gives you the full address, including the code and ZIP, and those two pieces need to match. Write the code with no punctuation and no spaces inside it. “FPO, A.P.” or “FPO A.P.” will not route.
What Never Goes on an FPO Address
Leave off the foreign country and the foreign city, even if you know exactly where the ship is docked or where the base sits. Adding “Yokosuka, Japan” or “Bahrain” pushes the piece into that country’s civilian postal system, where a military unit number means nothing.4USPS. How Do I Address Military Mail Write “FPO” on the line where you would normally write a U.S. city, and stop there.
Do not address FPO mail to “Any Service Member.” Every piece has to go to a specific named individual. Groups like the USO run separate programs for people who want to support troops without a specific recipient in mind.
Always write your own return address on the envelope or package. USPS requires it, and if a customs form or the delivery address has a problem, the return address is the only thing that keeps the piece from being destroyed.1United States Postal Service. Military and Diplomatic Mail
Shipping and Customs Once the Address Is Right
Only USPS delivers to FPO addresses. UPS, FedEx, and other private carriers cannot make final delivery to a military installation overseas; a package handed to them with an FPO address gets rejected at intake or returned. Start at usps.com or your local post office.
Domestic postage rates apply across Priority Mail, Priority Mail Express, First-Class Mail, and USPS Ground Advantage.1United States Postal Service. Military and Diplomatic Mail USPS also sells a Priority Mail APO/FPO/DPO Flat Rate Box at a discount to the standard large flat rate box, free to order from usps.com, with a flat price regardless of weight up to 70 pounds.5United States Postal Service. Notice 123 – Price List
Even though the postage is domestic, the mail physically leaves the country, so most FPO shipments need a customs declaration form. A customs form is required if the piece weighs 16 ounces or more, or if it contains any physical goods regardless of weight; a card with a gift card tucked inside counts.6United States Postal Service. DMM 703 – Nonprofit USPS Marketing Mail and Other Unique Eligibility Since July 2024, USPS has been returning non-compliant packages rather than forwarding them.7United States Postal Service. Management Instruction FM-640-2023-1 – Postal Bulletin 22652
The specific form depends on the mail class. Priority Mail Express uses PS Form 2976-B. Other classes use PS Form 2976 or PS Form 2976-A. Handwritten customs forms are no longer accepted; the form has to be computer-generated. The simplest route is Click-N-Ship on usps.com, which picks the right form from the destination ZIP. If you prefer the counter, fill out PS Form 2976-R as a worksheet and the clerk generates the label.8United States Postal Service. 123 Customs Forms and Online Shipping Labels Describe each item plainly with quantity and value, something like “cotton t-shirts (3), chocolate bars (6), paperback books (2).” “Gift” or “misc. items” is not enough and gets pieces flagged or returned.
Practical Tips That Protect the Address
Slip a piece of paper inside the package with both the delivery address and your return address. If the outer label tears or gets water-damaged in transit, the military mail clerks can still route the package from what is inside.1United States Postal Service. Military and Diplomatic Mail
Print. Do not use cursive, and do not decorate the address block. FPO mail passes through automated sorting equipment before it ever reaches the military network, and machines read printed capitals cleanly.
Confirm the ZIP and code with the recipient before you ship anything expensive or time-sensitive. Service members transfer between units and between ships, and an old address in your contacts can send a package on a long trip to nowhere. A quick message asking “what’s your current mailing address?” is worth the minute.