The FPO address format
An FPO address uses the same three-line shape as every military address. This is USPS’s own FPO example:
- Line 1 is the recipient’s rank or rate and full name.
- Line 2 is the unit and box.
- Line 3 is FPO, the region code (AA, AE or AP) and the ZIP.
Addressing a ship
Mail for a sailor aboard a ship names the ship. The ship name and hull number go on the line directly above the FPO line, where a unit and box would otherwise sit:
“USS Example” is made up. Use the ship name and hull number exactly as the crew member gives them to you.
Don’t add a port, a country or the ship’s location. The FPO line is the only routing the label needs, and which ship a ZIP serves isn’t published, which is deliberate. Ships move, and the sailor knows the current address, so get it from them.
FPO ZIPs and region codes
USPS assigns each ZIP to exactly one of APO, FPO or DPO. You can’t pick FPO because the recipient is in the Navy. The ZIP has to be an FPO ZIP. For instance, 09618 is an FPO ZIP, so “FPO AE 09618” is right and “APO AE 09618” is wrong.
The region code has to match the ZIP too. ZIPs starting 09 are AE, 340 are AA and 962 through 966 are AP. The sample above uses 96691, an FPO ZIP in the AP region. See what AA, AE and AP mean.
Common FPO mistakes
- Writing APO on an FPO ZIP (or the reverse). It’s a common mistake, and the checker flags it. How APO, FPO and DPO differ.
- Adding a country or port. Leave it off. The FPO line routes the mail.
- Putting an account or reference number directly above the FPO line. USPS reads the line right above the FPO line as the delivery address, so the unit or ship line belongs there.
- Dropping the leading zero on ZIPs that start with 0.
- Addressing it to “Any Sailor”. USPS requires a specific named recipient.
Shipping to an FPO address
FPO mail is domestic mail at domestic rates, and most ZIPs need a customs form for anything 16 ounces or heavier. The rules are covered in shipping to APO, FPO and DPO addresses, and each ZIP’s restrictions are on its own page, linked from the ZIP code list.
Questions about FPO addresses
What does FPO stand for?
Fleet Post Office. FPOs serve Navy and Marine Corps units and ships. Army and Air Force units use APO, and U.S. embassies and consulates use DPO.
How do I address a letter to a sailor on a ship?
Write the sailor’s rank and full name, then the ship name and hull number the sailor gave you, then FPO, the region code and the ZIP. Leave off the port and country.
Is FPO mail domestic?
Yes. USPS treats FPO mail as domestic and charges domestic rates. If a form asks for a country, choose United States.
Can an FPO address use an APO ZIP code?
No. USPS assigns each military ZIP to exactly one of APO, FPO or DPO, and the designation on the label has to match the ZIP.