Difference Between EAN-13 and UPC-A Barcodes

All UPC-A Barcodes are in essence a subset of EAN-13 Barcodes. If the first digit on the EAN-13 number is a ‘0’, then the image (the actual bars) of both the EAN-13 and the UPC-A will be identical. The format of the human readable numbers below the bars is different between the EAN-13 and the UPC-A barcodes, but this is the biggest difference between EAN-13 and UPC barcodes. Both formats can be easily scanned by the majority of barcode scanners.

When To Use EAN-13 vs. 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 throughout the world accept barcodes in either format. However some retailers may still use older systems that only accept one or the other format. Therefore if you are selling your products in the USA, the UPC-A format barcodes are your best choice. If your product is international or sold in a country other than the USA, then the EAN-13 Barcode is best for you.

If you come across 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. When 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.

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

Why does this occur?

Each digit is encoded into a barcode as a combination of 7 blocks of either white or black ink. A full 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 original 12 digit UPC system was created in the 1970’s by George Laurer and the UPC code works with 2 different parities – a left side odd parity and a right side even parity (each with 6 digits).

The 13 digit EAN-13 system was introduced later as a superset of the UPC barcodes. The system was deliberately designed to be used in conjunction with UPC-A barcodes.  It employed both the left odd parity and the right even parity of the UPC barcodes, but it also added an additional parity (a left-even parity), which was to be used on a selection of the left hand side digits.

The left and right hand sides of the EAN-13 barcodes are still divided into 6 digits each. So the function of the initial digit is to determine which combination of the first 6 digits will use the newly created left even parity. Therefore, while the first digit is not encoded in any EAN-13 barcode, it does determine the way the other digits are encoded.

In the case of a leading ‘0’ as with our barcodes, the leading 0 determines that all of the initial 6 digits will use the left odd parity (same as in UPC barcode encoding). This means that the bars of an EAN-13 barcode are encoded to look exactly the same as the bars of a UPC barcode without the leading ‘0’.

How do they scan?

Scanners do not read the digits below the barcode, only the actual bars.  Therefore an EAN-13 barcode with a ‘0’ on the front can sometimes be confused by scanners with a UPC barcode without the ‘0’ and vice-versa. This stems mostly from what the scanner or software system are expecting to see. When a barcode that has not yet been entered into the seller’s system is scanned, the software has no point of reference to determine the barcode format and it assumes that it is a UPC. When a barcode number is added to the system in the 13 digit EAN-13 format and linked to the product prior to scanning the barcode, things tend to work well. This is generally how stores proceed – first entering into their system the product barcode and related information provided on their buyer form.

Very few stores have had issues with this in the past and when issues do occur, they are generally resolved easily.


Please contact us if you have any questions about this.

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