Feature Zip Code Record For Free

A 5-digit number that identifies a particular postal delivery area in the United States.

So what do the extra numbers mean? These last 4 digits represent specific delivery routes within delivery areas. This extra detail means an even more precise matching to a more granular level. It could represent a handful of houses on one side of a street, or even a single building that receives a high volume of mail.

Because ZIP+4 codes are based on delivery routes, they change when the postal delivery routes are updated by the USPS. That's why ZIP+4 codes can change as often as once a month, since there are several factors that can result in the USPS updating its delivery routes.

The Census Bureau offers a few statistical products by ZIP Code through our economic surveys. These data are available through data.census.gov. Please contact the US Postal Service for additional information about ZIP codes.

Looking up a ZIP+4 with the USPS ZIP Code? Lookup Tool Enter the address you want to look up in the ?Street Address? field. You can also enter a city and state or a ZIP code to narrow down your search. Click the ?Find? button to search for the ZIP+4 code associated with the address.

11111 is not a valid 5 digit ZIP Code, but there are valid ZIP Codes that start with 111: 11101, 11102, etc. Once position 28 was changed to Y, then MSP considered 11111 as an Invalid zip, because it looked at all 5 digits.

It will still be delivered as long ass the rest of the address is correct. The USPS system corrects bad Zip Codes automatically by looking up the address in the database of all good addresses. We live in the 21st century and this is so easy for the computers to do now.

Census tracts have well known/exact boundaries. ZIP codes are groups of lines whose exact structural definition is not officially established.

What are unique ZIP codes? In short, unique ZIP codes are high volume mail receivers that receive mail at one location and then distribute the mail internally. Unique ZIP codes generally are used by large organizations, government buildings, universities or large medical facilities.

NON-UNIQUE This ZIP Code type is assigned to standard ZIP Codes with normal street delivery. PO BOX Represents Post Offices Boxes. UNIQUE This ZIP Code type is associated with a specific company or organization.