The Difference Between EAN-13 and UPC-A Barcodes

UPC-A barcodes are actually a subset of EAN-13 barcodes. If the first digit of the EAN-13 number is a ‘0’, then the bars of both the EAN-13 and the UPC-A are identical (without the leading ‘0’). The shifting of the human readable numbers below is different for UPC-A and EAN-13 barcodes, but this is the main difference. Both barcodes are easily scanned by most scanners.

When should you use an EAN-13 versus a UPC-A??

UPC-A format barcodes have traditionally been used in the USA, while EAN-13 format barcodes have been used throughout the rest of the world. Today, the majority of stores around the world accept barcodes in both formats. However, there may be some older systems that only accept one or the other. This means that if your product is sold in the USA, UPC-A format barcodes are best, but if your product is international or sold in a country other than the USA, an EAN-13 barcode is best.

If you encounter a store that has difficulty reading your EAN-13 or UPC-A barcode, they can either ignore the leading ‘0’ or add a leading ‘0’, depending on how many digits their system prefers. If this is done, the barcode will read exactly the same as the opposite format (as the bars are identical regardless) and will still be globally unique.

Both UPC and EAN-13 numbers can be purchased here. – If you require a UPC-A format barcode, please specify this in the additional information section when you are checking out.

How do EAN-13 and UPC-A bar codes work?

The way a digit is encoded in every barcode is by 7 blocks of either white or black that make up each digit. – A complete set of digits 0-9 is called a parity. – Retail barcodes have at least 2 parities, one for the left and one for the right. – This is so that they can be scanned upside down and still return the correct number upside down.

Originally, the 12-digit UPC system was created by George Laurer in the 1970s. – These use 2 different parities – an odd parity on the left and an even parity on the right (each with 6 digits) – the parities for these can be seen in the attachment.

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. It used both the left odd parity and the right even parity of the UPC barcodes, but added an additional parity (a left-even parity) to be used on a selection of the left-hand side digits – the left-even parity.

The left and right sides of EAN-13 barcodes are still divided into 6 digits each. So the first digit determines which combination of the first 6 digits will use the newly created left even parity. So in no EAN-13 barcode is the first digit actually encoded in the barcode, but it does determine how the other digits are encoded.

– In the case of a leading ‘0’, as in our barcodes, the 0 determines that all of the first 6 digits will use left odd parity, meaning that the bars will look the same as a UPC barcode without the leading ‘0’ – as the UPC version also uses only odd parity.

How do they scan?

The barcode scanner only registers the bars of the barcode and not the digits beneath it. Therefore, an EAN-13 barcode that begins with a ‘0’ may be misinterpreted by the scanner as a UPC barcode without the ‘0’ and vice versa. This error happens because it depends on what the scanner or software anticipates. This often occurs when the system scans an unlinked barcode. The software has no reference point to identify the barcode format, so it assumes it’s a UPC. The barcode is more likely to scan as an EAN-13 format if it is first added to the system in 13 digits and linked to the product based on the purchase form information that stores generally use.

Very few stores have had problems with this in the past. And if there are problems, they are usually easily resolved. If you’re going to the Musgraves in Ireland, they prefer that you fill in your barcode in its UPC format on their purchase form (without the leading ‘0’) and state that the format is UPC – if this is done, they have no problem using our barcodes.


Please contact us if you have any questions about this.

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