UPC(pronounced as separate letters) Short for Universal Product Code, a unique 12-digit number assigned to retail merchandise that identifies both the product and the vendor that sells the product. The UPC on a product typically appears adjacent to its bar code, the machine-readable representation of the UPC.
The first six digits of the UPC are the vendor��s unique identification number. All of the products that one vendor sells will have the same first six digits in their UPCs. The next five digits are the product��s unique reference number that identifies the product within any one vendor��s line of products. The last number is called the check digit that is used to verify that the UPC for that specific product is correct.
The check digit verification works like this, using the UPC 438571639853 as an example:
- The digits in the odd positions are added together: 4 + 8 + 7 + 6 + 9 + 5 = 39
- That number is multiplied by 3: 39 x 3 = 117
- The digits in the even positions (except for the 12th digit) are added together: 3 + 5 + 1 + 3 + 8 = 20
- This sum is added to the value in step 2: 117 + 20 = 137
- The check digit is the number that when added to that sum - 137 - equals a multiple of 10: 137 + 3 = 140, therefore the check digit for the above UPC is 3, which appears as the last digit of the UPC.
Each time that a UPC is read, typically by a scanner reading the bar code, this calculation is done. If the check digit is different than the one that is calculated, then the computer knows that there is something wong with the UPC.
Anyone wishing to use the UPC system must first apply for the rights through the Uniform Code Council.
Tape clearly is on the decline. But remember, legacy systems can hang for a shockingly long time. Read More »Apple Pay Promises to Strengthen Payment Security
Experts believe that Apple Pay and other competitive payment systems will be far more secure than cards, even cards equipped with EMV chips. Read More »Internet of Things Shaping IT's Future
To make the IoT both work and pay off, IT is juggling upgrading and building app-centric networks, mapping out new data center architectures and... Read More »
This Webopedia study guide describes the different parts of a computer system and their relations. Read More »Webopedia Polls
The trend for the past two years has been for shoppers to spend more online during the holiday season. How do you typically shop for holiday... Read More »How to Create a Desktop Shortcut to a Website
This Webopedia guide will show you how to create a desktop shortcut to a website using Firefox, Chrome or Internet Explorer (IE). Read More »
Stay up to date on the latest developments in Internet terminology with a free weekly newsletter from Webopedia. Join to subscribe now.
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »