Difference Between EAN-13 and UPC-A Barcodes
UPC-A Barcodes are basically a subset of EAN-13 Barcodes. If the first digit on the EAN-13 number is a ‘0’, then the bars of both the EAN-13 and the UPC-A (without the leading ‘0’) will be identical. The displacement of the human-readable numbers below differs between the UPC-A and EAN-13 barcodes; however, this is the most significant difference between the two. Both barcodes can be easily scanned by the majority of scanners.
When Should You Use an EAN-13 vs a UPC-A?
UPC-A Format barcodes have traditionally been used in the USA, whereas EAN-13 format barcodes have been used throughout the rest of the world. Nowadays, the majority of stores worldwide accept barcodes in either format. However, there might be some older systems that only accept one or the other. This means that if your product is being sold in the USA, the UPC-A format barcodes are recommended; however, if your product is international or sold in a country other than the USA, an EAN-13 Barcode is preferred.
If you come across a store that struggles to read your EAN-13 or UPC-A Barcode, they can either ignore the leading ‘0’ or add a leading ‘0’ depending on which format their system prefers. If this is done, the barcode will read the same as the opposite format (since the bars are identical), and will still be globally unique.
Why this happens
The way a digit is encoded in every barcode is by using seven blocks of either white or black, making up each digit. A complete set of digits 0-9 is called a parity. – Retail barcodes have a minimum of 2 parities, one for the left side and one for the right. – This is so they can be scanned upside down and still return the correct number the right way around.
Initially, the 12-digit UPC system was created in the 1970s by George Laurer. – these work with two different parities – a left side odd parity and a right side even parity (each with six digits) – the parities for these can be seen in the attached.
Later, a 13-digit EAN-13 system was introduced as a superset of the UPC barcodes. These were deliberately designed to be used in conjunction with UPC-A barcodes. And hence, employed both the left odd parity and the right even parity of the UPC barcodes, but added parity (a left-even parity) which was to be used on a selection of the left-hand side digits –
The left and right sides of the EAN-13 barcodes are still divided into six digits each. So the initial digit determines which combination of the first six digits will use the newly created left even parity. Hence, in no EAN-13 barcode is the first digit encoded in the barcode; however, it does determine the way the other digits are encoded.
– In the case of a leading ‘0’ as with our barcodes, the zero determines that all of the initial six digits will use the left odd parity, meaning that the bars look the same as a UPC barcode would without the leading ‘0’ – As the UPC version also only uses the odd parity.
How do they scan?
Because the actual bars are the only part of the barcode that is scanned (i.e the scanner isn’t reading the digits below the barcode), an EAN-13 barcode with a ‘0’ on the front can sometimes be confused by scanners as a UPC barcode without the ‘0’ and vice-versa. This is primarily due to what the scanner or software system is expecting to see. Often, this occurs when a barcode that is not linked to the system is scanned. The software has no point of reference for the barcode’s format and, hence, assumes it is in UPC format. When the number is first added to the system in the 13-digit format and linked to the product in the system (this is generally how stores add the barcodes based on the information provided on their buyer form), it tends to scan appropriately as an EAN-13 format barcode.