Wherever you go, the grocery store, department store, online at Amazon, or your refrigerator or pantry, you’ll find that everything purchased has a UPC barcode on it. Sometimes they are a little hard to find, but if you flip the package around, it’s there.

In this series, we will demystify UPC and EAN barcodes so that you have a better understanding of how they work.

A barcode is an optical machine-readable representation of data. One of the first uses of barcodes was to label railroad cars. Still, they were not commercially successful until they were used to automate supermarket checkout systems, a task in which they have become almost universal.

Systems such as RFID are attempting to change the standard, but the simplicity, universality, and low cost of printed barcodes has limited the role of these other systems. It costs less than one-half of one cent to implement a printed barcode compared to seven to thirty cents to implement a passive RFID.*

George Joseph Laurer developed the Universal Product Code in 1973. As an engineer at IBM, he was asked to develop the pattern used for the Universal Product Code (UPC-A Barcode).

GS1, which used to be called the Uniform Code Council (UCC), is the provider of UPC barcode prefixes. A company goes to the GS1, purchases the prefix, and then is responsible for the self-assignment of the identification numbers that go after the prefix.

The Barcode prefix, the first 6, 7, 8, or 9 digits, is called a UPC Barcode Prefix The company who has been assigned the UPC Barcode Prefix is responsible for the assignment of the next digits (making up a total of eleven digits) to their products.

Then, as the barcode number is designated, the last number is mathematically determined through an algebraic equation to create a checksum (check digit). This check digit is the final digit. When you join GS1, you get a prefix certificate along with your start-up package.