Stupid Question ™
March 22, 2004
By John Ruch
Q: When businesses put a UPC label on their product, how do they know it won’t be the same as that of another product?
—Aaron Brown, Columbus, Ohio
A: The Universal Product Code (UPC) label, that famous bar code that appears on most every product today, includes a unique manufacturer number assigned by the industry group that invented the code. That kills any confusion between manufacturers.
The rest of the code is an item ID number selected by the manufacturer itself. They know it won’t be the same as another one of that company’s other products, because some quality-control employee’s head will roll if it is.
Let me pause to commend you on the intelligence of your question. Many people mis-call the UPC the “Universal Price Code,” an error that seems to have grown naturally out of the way the code’s instant price scan revolutionized the checkout line.
But your question focuses on its main intent: inventory control.
The UPC was invented, and is still administered, by the Uniform Code Council, Inc. (UCC; originally the Uniform Product Code Council). It’s now based in New Jersey and has broadened to include other inventory-control systems, but the UPC brain trust still resides in Dayton, Ohio, where the code was invented. It was first used in a Troy, Ohio, supermarket in 1974.
To use the UPC, a company has to become Uniform Code Council member and pay an annual fee based on its revenue and the number of products it’ll be tagging. The council doesn’t bandy the numbers about, but hundreds to thousands of dollars is a typical fee.
The company is then assigned a unique “UCC Company Prefix” number. Classically this was a five-digit number, though it’s up to six in a new generation of longer UPCs. In any case, it’s always the first set of digits printed under the bars (and also encoded in those bars) in the UPC label.
The Company Prefix is printed in a UCC directory for all members to see. A nice, round number ending in three zeroes has real UPC cache—it typically means a great old industrial monolith that got into the UPC thing early.
For example, Campbell’s Soup has always been 51000. You can even use the Company Prefix to chart the byzantine world of corporate mergers; 43000 used to be General Foods, but is now the code for some of the Kraft/Nabisco family of companies, thanks to tortuous buyouts.
The other digits under the bar code (and also encoded within it)—again, classically five digits, but today often six—constitute the Item Reference Number, which identifies the company’s specific product being labeled. It is this part that makes the UPC unique for each type of item.
The UCC has nothing to do with assigning the Item Reference Number and is not notified about them. It doesn’t even know how many individual UPCs there are out there. It’s up to the company to keep them straight. The company can make it any number it wants, as long as it’s the proper number of digits. Most just count upward from 00000 for each new product.
For example, this can of old-fashioned Campbell’s tomato soup I just pulled off my kitchen shelf has the equally old-fashioned Item Reference Number 00011. Very low.
You may see other, smaller numbers on the UPC label, just outside the bars or perhaps right under the last couple of bars.
When the number appears on the left, this is a product type digit that indicates whether the product is a normal item or some time of special creation or sale item. Generally, 0 means it’s a normal item.
When the number appears to the right or under the last few bars, this is the “check” digit that makes sure the UPC has printed correctly. The number is derived from the preceding code numbers by a mathematical calculation provided by the UCC.
Even if the digit isn’t printed numerically on the label, it’s always encoded in the UPC bars. The scanner can automatically check it, thus determining both whether the UPC is genuine, misprinted and/or has been tampered with.