In the retail field, two barcode formats are mainly used, UPC and EAN. The UPC format (as shown in the figure below) is 12 digits, while EAN is 13 digits. These two formats are mainly used in their respective regions. UPC is only used in the United States and Canada, while EAN is used in other parts of the world.
U.P.C. stands for Universal Product Code (also known as: UPC-A) and E.A.N. stands for European Article Number (also known as: EAN-13 or International Article Number). UPC is the original format for product barcodes in the 1970s. Later, as demand in Europe, Asia, and Australia grew, the country code was added to the front of the barcode number, increasing it to 13 digits. The country code for the U.S. and Canada is zero, and the code is not printed under the barcode or entered into the U.S. and Canada inventory point-of-sale system.
If you look at the above graphics side-by-side with EAN barcodes and UPC barcodes, you will find that they are exactly the same. The width of the bars and the width of the space between the bars are exactly the same. The only major difference is the location of the numbers below (human readable numbers), these numbers are only for backup, in case the barcode cannot be scanned correctly and the information must be manually entered into the cash register, POS (point of sale system).
The image on the left covers the UPC and EAN graphics, so you can see that the images are the same. The country code will not appear under the barcode in the UPC, because GS1 did not take the importance of indicating country codes in the United States and Canada at the time. GS1 believes that since most of the products sold in these two countries come from importers, distributors, or manufacturers in the U.S. or Canada, they can abandon the leading zero in humans readable numbers.
If you currently only do business in the U.S. and Canada, it is recommended that your products use UPC barcodes. Many retailers, especially smaller retailers, may use old inventory systems that only allow them to enter a 12-digit UPC number instead of a 13-digit string. If this situation changes in the future, you can convert the 12-digit UPC to the 13-digit EAN by adding the country code 0 at the beginning.