Primary state prefixes. ZIP Codes are numbered with the first digit representing a certain group of U.S. states, the second and third digits together representing a region in that group (or perhaps a large city) and the fourth and fifth digits representing a group of delivery addresses within that region.

The standard ZIP code notation used by the United States Postal service uses five digits to identify a delivery area. An example of a standard US ZIP code is 90210.

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.

As of 1963, zip codes' numbers are determined by a few factors: the area, the regional postal facility and the local zone.

To create a personal Zip, a postal customer would go to a postal web site, authenticate who they are, much as they do today to sign up for Informed Delivery, and provide their current address and, optionally, email address. The system would provide them their own 11 (or 12) digit Personal Zip Code.

In-person transactions: When you use your debit card for in-person purchases at a physical store or restaurant, you typically do not need to provide a zip code. The card can be swiped or inserted, and you may need to sign or enter a PIN for verification.

To unzip a single file or folder, open the zipped folder, then drag the file or folder from the zipped folder to a new location. To unzip all the contents of the zipped folder, press and hold (or right-click) the folder, select Extract All, and then follow the instructions.