National Address Server Provides Nine-Digit Zip Code For Any U.S. Address

Release Date: July 27, 1995 This content is archived.


BUFFALO, N.Y. -- Have you ever wanted to mail a letter, but you didn't know the ZIP code for the address?

That's no longer a problem if you can access the WorldWideWeb, where the National Address Server will provide you with the ZIP+4 code for any residential or commercial address in the United States.

Developed by computer scientists in the Center of Excellence for Document Analysis and Recognition (CEDAR) at the University at Buffalo, the server is a comprehensive provider of all ZIP+4 information.

It was recently chosen by Apple Computer to be linked to Apple's eWorld on the WorldWideWeb. The server is listed on the Library page of WebCity, the company's consumer site on the Web -- in between the Virtual Reference Desk and the U.S. Constitution. The URL (Universal Resource Locator) address is

It also may be accessed directly at, also a URL address.

Users simply type in the name, street address, city and state and the server responds with the ZIP+4 code.

While the five-digit ZIP code identifies at least the destination post office, the ZIP+4 code reveals the side of the street, or even the house or building, where the letter's final destination is located.

"An important aspect of the National Address Server is that the system will clean up the address if there are slight errors in it," said Sargur Srihari, Ph.D., CEDAR director and UB professor of computer science. "If, for example, you type in 'Maple Avenue' when the proper location is 'Maple Road,' the server will correct it for you and provide the complete ZIP+4 code."

An added bonus, Srihari pointed out, is that the server also will provide the appropriate computer barcode for the address, which then can be sprayed onto an envelope through the user's printer.

Barcoded letters have a greater likelihood of making their way through the mail stream quickly than do those without barcodes, Srihari explained.

The National Address Server is a byproduct of years of research that CEDAR scientists have been performing for the U.S. Postal Service to develop a computer vision system that can read handwritten addresses. The project's purpose is to greatly reduce the amount of time and money it takes to process mail with handwritten addresses.

That system is designed to determine the ZIP code and the ZIP+4 code, if missing or incorrect, based on a database the researchers compiled of all U.S. addresses. The National Address Server was developed from that database. It was created as a Web page by UB doctoral candidate Ajay Shekhawat.

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