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Barcode Format – EAN & UPC

There are two main formats of barcode numbers; 13-digit EAN13 numbers and 12-digit UPC numbers. The UPC numbers are more commonly used in the USA, and the EAN13 numbers are used in the rest of the world. This is because they are part of the same system – the UPC numbers are a subset of the larger EAN13 system. In addition, these numbers are protected – so you need to purchase these barcode numbers if you want to use them on your retail products.

We usually supply barcode numbers in 13-digit EAN-13 format, with a leading 0 (e.g. 0799439112766 ). However, these numbers can also be used in 12-digit UPC-A format without the leading 0 (e.g. 799439112766 ). The actual bars produced for both of these are identical (see the picture below).

In South Africa, printing the barcode on products in the EAN-13 format is common. However, some retailers have software systems that don’t like numbers with a leading 0; they prefer to use your barcode in the 12-digit format (e.g. 799439112766 ). This is fine – the number is still the same and still unique and will work OK. You can let the retailer determine which version of your barcode number they will use.

To buy a barcode for your retail product, look here.

And look here for more information about what makes Barcode1 different.



Why this occurs?

The way a digit is encoded into every barcode is 7 blocks of either white or black, making up each digit. – 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 right way around.

Originally 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-hand 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, the 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 0 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 largely to do with 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 what format the barcode should be and, hence, assumes that it is UPC format. However, 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.

Very few stores have had issues with this in the past. And when issues occur, they are generally resolved easily. For example, if you are going to the Musgraves in Ireland, they prefer that you fill out your barcode in its UPC format on their buyer form (without the leading ‘0’) and state that the format is UPC – if this is done, they have no problems using our barcodes.

Please contact us if you have any questions about this.