Barcodes are an essential part of today's economy. The small sticker on most items we buy can contain a wealth of information and are used by manufacturers, wholesalers and retailers for managing inventory and quickly identifying the price of an item. Not only do they save time, but they also remove the factor of human error when it comes to counting or pricing items.
Other barcodes, like those used by the USPS, or those used by pharmaceutical companies, can contain even more information about an item, revealed by a quick scan with a barcode reader.
The numbers below a barcode are merely a translation of what the bars above mean to a barcode scanner. Humans can read the numbers, but barcode scanners cannot.
The most common barcode American consumers see is the Universal Product Code (UPC) or the EAN-13. Both of these are used to identify a product for inventory and pricing purposes. When you hear a beep at the grocery store checkout, that's almost always the sound of a UPC sticker being scanned.
UPC-A: Often shortened to UPC, this is the standard retail barcode used in the United States and Canada.
UPC-E: This is used on small items that don't have enough space for a UPC-A label. It contains the same information as a UPC-A barcode, but the data is compressed to keep it within six digits.
EAN-13: This is the international version of UPC-A barcode. It contains 13 digits. It can also be read by UPC barcode readers in the United States.
EAN-8: Like the UPC-E, this is an eight-digit barcode used when the EAN-13 barcode would be too large.
ISBN-13: This is the barcode used on books, consisting of 13 digits. It conforms to EAN-13 standards.
ISMN: Similar to an ISBN, this is used for sheet music and conforms to EAN-13 standards.
Code 128: This barcode can encode all letters, numbers and punctuation in the 128-character ASCII set. It can be used when more information is required beyond pricing and inventory purposes.
Code 39: This is another alpha-numeric barcode, like Code 128, but it takes up more space.
Pharmacode: This barcode is used by pharmaceutical companies for security and packaging control. It uses multiple colors.
Intelligent Mail Barcode: This is the barcode system used by the U.S. Postal Service for routing mail. It contains the ZIP code plus additional delivery point codes. With 65 variable-height bars of four different types, this barcode is replacing the Postnet barcode, which had more limitations.
2D Barcodes: Unlike other barcodes, which are one-dimensional, 2D codes represent data in two dimensions, much like the squares on a chessboard. These cannot generally be read by barcode scanners, but can be read by most smartphones.
Most retailers require that manufacturers provide them with a unique Universal Product Code (UPC) before they will agree to sell a product. Not only does scanning a barcode save time at the cash register, but it also allows the retailer to track inventory more efficiently. UPC barcodes only identify a product and do not contain data on a product's price. Pricing information is usually contained in the retailer's database, associated with that UPC number.
When a clerk scans a barcode, its number is found in the database and the software returns with the price. When the sale is completed, the unit is subtracted from the retailer's inventory. This means that if the retailer puts an item on sale, they only have to make a change in the database, rather than put a new barcode on each item during the sale.
UPC-A barcodes consist of 12 numbers. The first digit identifies the numbering system. The next five digits identify the manufacturer, while the second five digits identify the specific product. The last number is a check digit.
EAN-13 barcodes consist of 13 numbers. The main difference between EAN-13 and UPC-A codes is that the EAN-13 code has two numbers at the beginning identifying the number system, instead of one. The next five numbers are the manufacturer's code, while the five digits following identify the products. The last number is a check digit.
UPC-A codes can be considered a subset of EAN-13 codes. In fact, any barcode reader that can identify a UPC-A code can also read an EAN-13 code. If the code begins with a zero, it's always a UPC code.
In the United States, UPC barcodes are regulated by GS1 US, which assigns company prefix numbers to companies to ensure that every company, and thus each of the products it makes, has a unique barcode. UPC barcodes fall under the Global Trade Identification Number (GTIN) standard.
The 12 numbers you see at the bottom of a barcode are stored as 14-digit strings in a database. Companies that need less than 10 UPC barcodes can purchase them for $75 each, with an annual $10 license renewal fee. Companies that need more than 10 UPCs should apply for a GS1 Company Prefix through gs1us.org so they can produce their own barcodes.
Companies can also buy UPC barcodes from secondary sellers at reduced prices without renewal fees. These sellers typically issue a number using their own company prefix, however, they must have obtained their GS1 company prefix before 2001. Some retailers, such as WalMart and Kroeger, require uniquely assigned GS1 UPC barcodes. Some companies using an Electronic Data Interchange (EDI) may require a unique company prefix.
Contrary to a popular myth, you can't identify a product's country of origin simply by reading the first two or three numbers of a barcode. You can, however, determine which country issued the barcode number. GS1 numbers issued in the United States can begin with:
- 00001 – 00009
- 0001 – 0009
- 001 – 019
059 (reserved for future use)
However, if you are looking at a UPC-A barcode, it's likely that the first zero has been removed. The full number would appear on an EAN-13 barcode. Other country codes include:
379: France * 400 –
440: Germany * 460 –
469: Russia * 500 –
509: United Kingdom * 690
699: China * 750: Mexico
Whenever you buy fruits or vegetables at the grocery store, you're bound to see a four- to five-digit number on a small sticker. These are called Product Lookup (PLU) codes and, while they don't have bars on them and aren't bar codes, they are also used for managing inventory and getting the prices for items that are sold.
Most produce PLU codes are four-digits long. Bananas, for example, are 4011. Organic produce uses the same code with a 9 preceding it, while genetically-modified produce begins with an 8. So, for example, organic bananas use the code 94011, while genetically-modified bananas would have the code 84011. PLU codes also depend on how the produce is sold, such as in bags, or if they have been cut. For example:
- Bagged carrots use 4094
- Loose carrots use 4562
- Cut carrots use 4563
When processing sales or taking in inventory, retail clerks can enter the PLU code, rather than doing barcode lookup, to get the price or update stock numbers.