EAN is designed by the International Article Numbering Association (EAN) in Europe. It is an extension to UPC-A to include the country information. The only difference between UPC-A and EAN-13 is that the number system in UPC-A is a single digit from 0 through 9 whereas an EAN-13 number system consists of two digits ranging form 00 to 99.

EAN-13 encodes 12 digits of numeric data along with a trailing check digit, for a total of 13 digits of barcode data.

An EAN-13 number consists of four areas: (1) The number System; (2)The manufacturer code; (3) the product code; (4)The check digit. Normally the number system digit is printed to the left of the barcode, and the check digit to the right. The manufacturer and product codes are printed just below the barcode, separated by the guard bar.

**Number System**. The number system is the first two digits in the EAN number to identify the country/region numbering authority. The number system list is maintained by GS1 organization (http://www.gs1.org).**Manufacturer Code**. The manufacturer code is a unique code assigned to each manufacturer by the numbering authority indicated by the number system code. All products produced by a given company will use the same manufacturer code.GS1 uses what is called “variable-length manufacturer codes”. The lengths generally vary between manufacturers.

**Product Code**. The product code is assigned by the manufacturer. The product code immediately follows manufacturer code. The total length of manufacturer code plus product code must be exact 10 digits.**Check Digit**: The check digit is used to verify that the barcode is generated or scanned correctly. The check digit is calculated based on the rest of the barcode digits.

**JAN**. Japan's numbering system is 49. The EAN numbers with numbering system 49 are called JAN.**Bookland**. The bookland barcode is an EAN-13 barcode that follows a specific format used exclusively with books (all bookland barcodes start with 978).^{[1]}

UPC-A check digit is calculated using standard Mod10 method. Here outlines the steps to calculate UPC-A check digit:

From the right to left, start with odd position, assign the odd/even position to each digit.

Sum all digits in odd position and multiply the result by 3.

Sum all digits in even position.

Sum the results of step 3 and step 4.

divide the result of step 4 by 10. The check digit is the number which adds the remainder to 10.

A web-based free utility to calculate UPC-A check digit is available at http://www.morovia.com/education/utility/upc-ean.asp.

A EAN-13 symbol can be divided into two halves, each consisting of six digits separated by a center guard bar pattern. The whole symbol is surrounded by two guard bar patterns. The same digit has different encoding depends whether it is in the left halve or in the right halve. The encoding pattern for digits in the left halve always starts with a space while the one for digits in the right halve always start with a bar and ends with a space.

A EAN-13 symbol has the following structure:

Start guard bars, always with a pattern bar+space+bar.

Left halve, six digits encoded using the encoding schema A or B;

Center guard bars, with a pattern space+bar+space+bar+space.

Right halve, six digits encoded using the encoding schema C.

Stop guard bars, always with a pattern bar+space+bar.

^{[1] }Traditionally books are identified by their
10 digit ISBN numbers which can be converted to EAN-13 by adding 978 prefix.
Now book industry uses EAN-13 numbers exclusively with leading prefixes
978 or 979. See ISBN-13
announcement.