When mailing a letter or package through the United States Post Office you are expected to prepare the recipient’s address information in a standard format. When mailing international mail there are a few additional requirements. For example, while a return address is suggested on outgoing mail, it is mandatory for international mail.
Clearly write the recipient's name on the first line. The last name is required, the first name or title is suggested.
Clearly write the street name and numbers or post office box number on the second line. Include any suite or apartment numbers.
City and State
Cleartly write the city and state on the third line in the address box.
Clearly write the zip code of the recipient in the final line of the address box.
The address printed on an envelope must be legible from an arm’s length away.
When addressing military mail the recipient’s full name, including a middle name or initial, ship or unit number, and PSC number must be included. When addressing military mail the recipients’ city is replaced with FPO or APO and the state is replaced with AP, AE or AA. A special ZIP code is also required.
When mailing international mail, the last line in the address box must be the destination country only. It must be printed in all capital letters and cannot be an abbreviation.