How to troubleshoot a Military/ APO Address

How to format military addresses properly and use APO, FPO, DPO etc.

A bit of background - when you send mail to a military base (active or inactive), you don't send it to the base's physical street address. Most of these locations are secure, and the exact address isn't listed or made available to the public. This helps military bases stay off the radar, and avoids unnecessary security risks. Instead of using a physical address, military addresses will need to be formatted in a specific, coded way.

Military sites are coded as either an APO, FPO, or DPO:

APO stands for Army Post Office and is associated with Army or Air Force installations.
FPO stands for Fleet Post Office and is associated with Navy installations and ships.
DPO stands for Diplomatic Post Office and is associated with U.S. Diplomatic locations.

Formatting:

There are seven main components to a valid APO, FPO or DPO address.

1. The name of the recipient. The rank/grade/rating is not required.

2. The type of address where the mail is going. This could include:

PSC (Postal Service Center)
CMR (Community Mail Room)
UMR (Unit Mail Room) or just Unit
RPO (Regional Post Office)
APO (Army Post Office)
OMDC (Official Mail Distribution Center)
For Navy or Coast Guard vessels, the ship’s name and hull number.

3. The number of that address. For example:

PSC 1234
Unit 7400
USS Nimitz (CVN 68)

4. The recipient's Military PO box number (if they have one).

5. The post office type (APO, FPO or DPO)

6. The "state" designator (either AA, AP or AE). These "states" represent the USPS mail processing facilities that handle the mail traffic to and from each military location.

7. The zip code, preferably ZIP + 4 (although not required)

That’s it! Here are some sample addresses that are formatted correctly for each post office type:

Here is a sample APO Address:

PFC John Smith

PSC 1234, Box 12345

APO AE 09204-1234

Here is a sample FPO Address:

John Smith

USS Cochrane (DDG-21)

FPO AP 96543-1234

Here is a sample DPO Address:

John Smith

Unit 8400, Box 0000

DPO, AE, 09498-0048

All of this information, as well as the correct format for sending mail to their location, should be readily available to the military member.

A few additional items to remember when sending Military Mail :

It is not necessary to add the specific military formation or the recipient's rank.
When mailing to a DPO address, do not add the street address of the embassy.
All APO, FPO or DPO packages will be shipped via USPS.
Orders shipping overseas can take approximately 5 business days to reach the APO, FPO or DPO hub. It will take additional time to receive your package from there. Delays are common, and unavoidable once the package/letter has been received on base.
All mail sent to the Military must be addressed to someone specific; addressing mail to "Any Service Member" is no longer permitted by the USPS.
Military Mail is treated as domestic (rather than international), and pricing will reflect that.
Don't forget about your Customs forms!

There are a few shipping restrictions for Military Mail:

Packages must weigh 70 lbs or less and cannot exceed 130" in combined length and girth
You cannot ship any items that are currently outlawed by USPS ( full list here)