Use stamps, a postage meter, or a PC Postage system to affix the correct amount. You can calculate postage online at pe.usps.com.
Name of Organization
Use a Post Office box or street address, but not both. If the address also has a directional (for instance, NW for Northwest), be sure to use it. There may be more than one Main Street.
Apartment or Suite Number
The correct apartment or suite number helps to ensure delivery to the right location.
City, State, and ZIP Code
To find the correct spelling of a city name or to find a ZIP Code, visit www.usps.com or call 1·800·ASK·USPS. Using the correct ZIP Code helps to direct your mail more efficiently and accurately.
Print the delivery and return addresses on the same side of your envelope or card. The addresses should be written parallel to the longest side.
Type or print clearly with a pen or permanent marker so the address is legible from an arm's length away. Do not use commas or periods.
A return address is required on most mail.
Express Mail® For Express Mail, you must use a USPS-produced address label provided by the Post Office.
Military addresses must show the full name with middle name or initial and the PSC number, unit number, or ship name. Replace the city name with APO, FPO or DPO, and the state with AA, AE, or AP, and use a special ZIP Code.
A list of commonly used state, street, and other abbreviations is available online.