Postal service zip plus four

As discussed above, it is difficult to precisely define a geographic area covered by a ZIP code. ZCTAs were developed to account for some of the difficulties in assigning an area to a ZIP code and to precisely define a geographic area. In general, they are updated once every 10 years for the Census. The Census assigns an area to a ZCTA according to census blocks the smallest geographic unit used by the census.

Imagine a city block that makes up a typical census block as pictured to the right. It is bounded on all 4 sides by portions of city streets that each have their own name and addresses. The issue is that census blocks almost always split down the middle of the street.

ZIP codes rarely do because that would require two postal workers delivering mail to that street - one for each side of the street. In the example, one mail carrier may deliver to 3 sides of the block via one ZIP code while another mail carrier delivers mail on the other street in a different ZIP code.

When this happens, the Census Bureau will assign the entire block to a single ZCTA in this case, because the census block is the area that is precisely measured. If you are getting very precise usually a matter of meters, not miles , census block boundaries near the edge of a ZIP code almost always split ZIP codes.

The statistics provided by the Census Bureau can give insight into the demographics within the ZIP code. For instance, see our ZIP code rankings. Auditing the Government's Books. Unpacking the Financial Report. Action Tracker. About This Work. Why It's High Risk. What Remains To Be Done. Key Reports. Flood Insurance. Past Pandemic-Related Reports. Report Suspected Fraud.

How to Get Notified. Past Reports. Public Health Threats. The last two digits represent a delivery segment, which might be one floor of an office building, a side of a street, specific departments in an office, or specific Post Office boxes. Locate a Post Office anywhere in the United States.

May 1 More and more companies are requiring it on paperwork and forms. These codes indicate a specific delivery route , meaning the actual path the mail truck would travel in a single drop-off. Usually this comprises ten to twenty homes or locations. Because ZIP codes plus 4 extra digits are based on delivery routes instead of more permanent boundaries, the last 4 digits of a complete ZIP Code can change often.

Not so for the full 9-digit ZIP Code. For another thing, they can help get you those bulk mailing discounts.

Another important benefit to using the last four digits of ZIP Codes is delivery speed. That's right, your mail can show up faster if you label things right. Bet you're scrambling for those codes now, huh? Get those extra 4 digits. If you want to try it on a single address, you can use our single address verification tool now. Go ahead and perform some postal address verification.