ZIP+4 Database

The United States Postal Service (USPS) added a 4-digit extension to the standard 5-digit ZIP Code in the 1980’s to facilitate mail sorting and delivery. They are commonly referred to as ZIP+4, ZIP Plus 4 and 9-digit ZIP Codes. Since then, the ZIP+4 databases have been used by organizations looking to add more precision to direct marketing efforts.

The 9-digit ZIP Code format includes the 5-digit ZIP Code in the first 5 places and then a 4-digit extension (AABB) representing the ZIP Code Sector and ZIP Code Segment. The ZIP Code Sector (AABB) refers to the geographic piece of a ZIP Code area such as city blocks or a large building. The ZIP Code Segment (AABB) refers to a very specific location such as a floor in a large building or a specific city block.

Because ZIP+4 records represent a much smaller set of households, companies can use them to narrow results for direct mail and marketing efforts. Also, because they include centroids, the data can be used for spatial analysis, including proximity calculations.

Yes, for each ZIP+4 record in the database, we include the geographic center point for the physical address range represented.

Maponics’ proprietary process builds the ZIP+4 Database Premium products from the raw USPS ZIP+4 data by geocoding the ZIP+4 address ranges against street segments to find the precise ZIP+4 centroids. The ZIP+4 ranges are then expanded, resulting in approximately 13 million additional ZIP+4’s. More specifically, a ZIP+4 can represent one side of the street, a floor in a building, or a specific Post Office Box. PO Box ZIP+4’s are initially represented by the United States Postal Service as a ZIP+4 low value and ZIP+4 high value, e.g. 200010001 - 200010486. Maponics expands these ranges to contain all the ZIP+4 values included within the initial ZIP+4 range set.

The Maponics ZIP+4 products include Census Block Group codes, which include state, county and tract codes for linking to the 9-digit ZIP Code records.

Please reference the ZIP+4 Product Documentation for the description and an example of the fields in the ZIP+4 products.

File size. There are more than 53 million ZIP+4 records and each have over 30 fields. That is a lot of data! Even zipped the file size is several gigabytes, which no other standard format could manage as easily. File size is also why the data will be tiled by state.

The coverage includes 50 States, D.C., Puerto Rico, and U.S. Military APO/FPO.