USPS Address Formatting and Requirements

We recommend making sure your address(es) are accurate and formatted properly before sending mail. This can be done a number of ways, including using the USPS address checking tool, searching for the address through Google Maps, or if you have many addresses contained within an excel file (.csv), we recommend using one of our address cleanup tools.

The minimum information that needs to be provided is the recipient name, street address, as well as the corresponding City, State, and Zip.

Attached is a sample template of a generic .csv file that you can use to help set up your mailing lists:  csv_sample.csv

The United States Postal Service (USPS) has a pretty well defined format that they'd like people to use.  In most cases they would like to see three lines of information, as follows:

  • Address (123 E MAIN ST APT 12)
  • City, State, Zip code (LOS ANGELES CA 90012)

Some things to keep in mind... the USPS:

  1. prefers addresses to be all upper case (capitalized) letters.
  2. doesn't like to see periods (.) or commas (,) in the address.
  3. prefer that the street direction (North, South, East, West) is abbreviated to N, S, E or W.
  4. perfers the type of street (Drive, Lane, Avenue, Street, Boulevard, Road) to be abbreviated to DR, LN, AVE, ST, BLVD or RD
  5. prefers the unit (Apartment, Suite, Room, Building, Department, Floor) to be abbreviated to APT, STE, RM, BLDG, DEPT or FL.
  6. prefers that a space is added between a number sign (aka pound sign, hashtag symbol (#)), and the actual number (i.e. # 12). But the number sign is not needed if you have the unit description (APT, STE, etc.) 
  7. doens't want abbreviated city names.
  8. likes the full 9-digit zip code (zip+4) (00000-0000), but the 5-digit zipcode will work.
  9. doesn't like both a street address and a PO Box to be included. If you have both to choose from, pick one to send to it. Don't use both as that will confuse the post office.

Keep in mind, you shouldn't stress over these items.  If you are uncertain and this document doesn't answer you questions, simply try your best and and send it out.  The USPS has been delivering mail for a long time and are pretty good at understanding what you mean.  However, there are some things that the USPS can't deliver your letter without; as you must have a complete street address, state, and a zipcode.

What about extra information, like company name?

Our service provides up to five (5) lines for your addresses.  That means we provide the three normal lines plus an extra Name line and an extra Address line (but you don't need to use them, and probably shouldn't use them unless you really need to). Here's an example of a 5 line address that would work, along with a 4 line version that would probably be preferred:

5 line address example (good)

LetterStream, Inc.

Attn: Sample name

8551 E. Anderson DR

Suite 108

Scottsdale AZ 85255

4 line address example (better)





We recommend using the second Name line for a Company Name, a Job Title, or an additional recipient living or working at the same address.  We don't recommend putting someone's last name only in the second name field.

We generally believe that a second address line is not needed, but sometimes it is convenient if you are importing data from a software package which keeps the unit number on a second line.  If you are typing an address, we recommend putting the unit number on the same line as the street address.

There might be occasions when you need three name lines.  If so, use the first address line for the third name and then put the complete address in the second address line.

Confused about what a street address is composed of?

The street address is similar to what you might type into google or apple maps so you can get to the specific address.  If you don't have a specific address for your letter, it will have a tough time getting there.

The street address if generally made up of these items:  

Street or House Number - Most houses and businesses have a specific number assigned to them so you can determine exactly which building on a particular street you are trying to find.  The US 911 system really needs people and businesses to have a street number on the building to help first responders get to the address without delay.

Street Direction - Most street names have a compass direction assigned to them.  This direction appears after the House Number and before the actual Street Name. While sometimes dual directions are used (North West) most of the times a single direction is used and is normally abbreviated to a single letter (N, S, E, W).

Street Name - This is the actual name of the street and could be almost anything.  The most popular street name is "Second".  "Main" is in the top 10.

Street Type - Some cities use the same street name in multiple ways, for instance there can be a Main Street and a Main Drive, so make sure to include the street type (drive, avenue, lane, boulevard, way, road, etc)

If we put it all together, 123 East Main Street.  But abbreviate it as 123 E MAIN ST.

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