UPC Bar Code Frequently Asked Questions (FAQ)
Are there different kinds of UPC barcodes?
Do UPC barcodes contain the item's price?
Who makes the rules and keeps track of all this?
How do you calculate a UPC barcode check digit?
UPC barcode trivia and errata.
UPC Frequently Asked Questions
UPC barcodes (Universal Product Code bar codes) are the symbols used on items in the retail channel. UPC barcodes get scanned at the cash register as part of a POS (point of sale) system. They contain unique numbers that identify one product from another. That's how cash registers can display and print receipts with the name and price of everything you buy.
Are there different kinds of UPC barcodes?
There are two types of UPC barcodes: UPC version A barcodes (12 digits) are the most common kind in the U.S and UPC version E are shortened versions (8 digits) used when space is at a premium. ISBN-13 barcodes (formerly called Bookland bar codes), based on ISBN numbers, are found on books and ISSN symbols are on non-U.S. periodicals. EAN-13 and EAN-8 are used outside the U.S. JAN-13 and JAN-8 are used in Japan.
Do UPC barcodes contain the item's price?
No, UPC barcodes don't contain a product's price. They are lookup numbers that uniquely identify items in the distribution and retail chain. When an item is scanned, the cash register looks that number up in the store's computer. The database returns the item's price, displays the name on the register and receipt, and subtracts the item from the inventory database. The price is in the database, otherwise having a sale would mean re-barcoding everything that was just on sale. As soon as the sale is over you'd have to re-barcode everything back.
The first thing a new manufacturer has to do is obtain their own company prefix from GS1 US, the standards body. The company prefix is used to build UPC barcodes. The company prefix forms the first portion of the 11-digits in a UPC barcode (12 if you count the check digit in the lower right corner). UPCTools creates UPC barcodes in things like Excel, Crystal Reports, Access, C/C++, VB, etc.
Who makes the rules and keeps track of all this?
GS1 US is the standards body that administers UPC barcodes in the U.S. GS1 dispenses company prefixes, publishes standards and guidelines, holds training and educational events, and certifies professionals in the industry. Links to other barcode standards organizations worldwide can be found here.
How do you calculate a UPC barcode check digit?
The 12th digit in a UPC barcode is a check digit based on the previous 11 numbers. How the UPC check digit is calculated is explained here.
UPC barcode trivia and errata.
Did you know that some people have barcode tattoos? This page has photographs of barcodes. And no, UPC barcodes do not contain 666 or the Mark of the Beast in them. Silly urban legend.