What Is Address Line 1 And 2 According To USPS Standards?

rochaworkmarie
Nov 19, 2023
2 min read

The USPS addresses a piece of mail or package based on the guidelines provided in its publication 28, “A Guide to Standardized Addressing.” While these addressing requirements differ slightly by country, there are 2 consistent elements that should be considered for each and every address.

In the US, the address elements in the delivery address line are broken up into a primary street name (or building number) with a suffix or apartment or suite number, a two character state abbreviation and a ZIP Code. One space must be left between each address element, punctuation is limited to periods, slashes and hyphens, and directional words must be abbreviated.

Despite this guidance, many online and paper address forms still include a second field for apartment or suite numbers. Although this information is technically valid, allowing it to be included in the primary address is not good practice for a variety of reasons.

For instance, secondary unit designators can cause confusion for mail carriers and couriers. They often are mistaken for other address components such as a care of or box number. Additionally, when address line 1 is also filled out with an apartment or suite number, it can be difficult for an address validation system to determine the original intended destination.

To avoid confusion, it is best to remove the address line 2 field from your digital or paper address forms. Instead, simply encourage your end users to add the apartment or suite number in a field above the primary address line 1. This will result in less confusion for everyone involved and cleaner data for your forms. Smarty’s US Autocomplete Pro API solves this problem by suggesting secondary unit designators for your end users, and then combining them with the primary address line to create an accurate and validated USPS address.