The following article explains what these files are, why they are packaged as ZIP archives, and how to safely download or use address data. Understanding National ZIP+4 Data Files
: Because of the massive file size, these databases are distributed as ZIP archives to save disk space and speed up transmission. Download File Nasbi4 zip
A National ZIP+4 Address Database is a comprehensive collection of roughly nine-digit codes. These codes identify specific delivery segments like city blocks or high-volume business receivers. The following article explains what these files are,
: To remain accurate, these databases are updated monthly to reflect new construction and postal changes. How to Download and Use These Files These codes identify specific delivery segments like city
If you are looking for specific address verification or ZIP+4 data, you should use official or certified providers: ZIP Code™ Lookup | USPS
: The data is typically stored in fixed-length ASCII records of about 182 bytes each.