International Article Number


The International Article Number is a standard describing a barcode symbology and numbering system used in global trade to identify a specific retail product type, in a specific packaging configuration, from a specific manufacturer. The standard has been in the Global Trade Item Number standard from the GS1 organization; the same numbers can be referred to as GTINs and can be encoded in other barcode symbologies defined by GS1. EAN barcodes are used worldwide for lookup at retail point of sale, but can also be used as numbers for other purposes such as wholesale ordering or accounting.
The most commonly used EAN standard is the thirteen-digit EAN-13, a superset of the original 12-digit Universal Product Code standard developed in 1970 by George J. Laurer. An EAN-13 number includes a 3-digit GS1 prefix. A prefix with a first digit of "0" indicates a 12-digit UPC-A code follows. A prefix with first two digits of "45" or "49" indicates a Japanese Article Number follows.
The less commonly used 8-digit EAN-8 barcode was introduced for use on small packages, where EAN-13 would be too large. 2-digit EAN-2 and 5-digit EAN-5 are supplemental barcodes, placed on the right-hand side of EAN-13 or UPC. These are generally used for periodicals like magazines or books, to indicate the current year's issue number; and weighed products like food, to indicate the manufacturer's suggested retail price.

Composition

The 13-digit EAN-13 number consists of four components:
The first three digits of the EAN-13 usually identify the GS1 Member Organization which the manufacturer has joined. Note that EAN-13 codes beginning with 0 are actually 12-digit UPC codes with prepended 0 digit. In recent years, more products sold by retailers outside United States and Canada have been using EAN-13 codes beginning with 0, since they were generated by GS1-US.
The 020-029 GS1 Prefixes are worth a special mention. GS1 defines this as being available for retailer internal use. Some retailers use this for proprietary products, although many retailers obtain their own manufacturer's code for their own brands. Other retailers use at least part of this prefix for products which are packaged in store, for example, items weighed and served over a counter for a customer. In these cases, the barcode may encode a price, quantity or weight along with a product identifier - in a retailer defined way. The product identifier may be one assigned by the Produce Electronic Identification Board or may be retailer assigned. Retailers who have historically used UPC barcodes tend to use GS1 prefixes starting with "02" for store-packaged products.
The EAN "country code" 978 has been allocated since the 1980s to reserve a Unique Country Code prefix for EAN identifiers of published books, regardless of country of origin, so that the EAN space can catalog books by ISBNs rather than maintaining a redundant parallel numbering system. This is informally known as "Bookland". The prefix 979 with first digit 0 is used for International Standard Music Number and the prefix 977 indicates International Standard Serial Number.

Manufacturer code

The manufacturer code is a unique code assigned to each manufacturer by the numbering authority indicated by the GS1 Prefix. All products produced by a given company will use the same manufacturer code. EAN-13 uses what are called "variable-length manufacturer codes". Assigning fixed-length 5-digit manufacturer codes, as the UCC has done until recently, means that each manufacturer can have up to 99,999 product codes. Many manufacturers do not have that many products, which means hundreds or even thousands of potential product codes are being wasted on manufacturers that only have a few products. Thus if a potential manufacturer knows that it is only going to produce a few products, EAN-13 may issue it a longer manufacturer code, leaving less space for the product code. This results in more efficient use of the available manufacturer and product codes.
In ISBN and ISSN, this component is used to identify the language in which the publication was issued and managed by a transnational agency covering several countries, or to identify the country where the legal deposits are made by a publisher registered with a national agency, and it is further subdivided any allocating subblocks for publishers; many countries have several prefixes allocated in the ISSN and ISBN registries.

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 should be 9 or 10 digits depending on the length of country code.
In ISBN, ISMN and ISSN, it uniquely identifies the publication from the same publisher; it should be used and allocated by the registered publisher in order to avoid creating gaps; however it happens that a registered book or serial never gets published and sold.

Check digit

The check digit is an additional digit, used to verify that a barcode has been scanned correctly. It is computed modulo 10, where the weights in the checksum calculation alternate 3 and 1. In particular, since the weights are relatively prime to 10, the EAN-13 system will detect all single digit errors. It also recognizes 90% of transposition errors.

Calculation of checksum digit

The checksum is calculated as sum of products - taking an alternating weight value times the value of each data digit. The checksum digit is the digit, which must be added to this checksum to get a number divisible by 10. See ISBN-13 check digit calculation for a more extensive description and algorithm. The Global Location Number also uses the same method.

Position - weight

The weight at a specific position in the EAN code is alternating in a way, that the final data digit has a weight of 3.
All Global Trade Item Number and Serial Shipping Container Code codes meet the next rule:
Numbering the positions from the right, the odd data digits are always weight of 3 and the even data digits are always weight of 1, regardless of the length of the code.
Weights for 18-digit SSCC code and GTINs :
position1716151413121110987654321
weight31313131313131313

Weights for EAN-13 code:
position121110987654321
weight131313131313

Weights for EAN-8 code:
position7654321
weight3131313

Calculation examples

The GTIN numbers, encoded to UPC-A, EAN-8 and EAN-13, all use similar encoding. The encoded data is usually repeated in plain text below the barcode.

Barcode structure

The barcode consists of 95 areas of equal width. Each area can be either white or black. From left to right:
To encode the 13-digit EAN-13 number, the digits are split into 3 groups; the first digit, the first group of 6 and the last group of 6. The first group of 6 is encoded using a pattern whereby each digit has two possible encodings, one of which has even parity and one of which has odd parity. The first digit is not represented directly by a pattern of bars and spaces, but is encoded indirectly, by selecting a pattern of choices between these two encodings for the first group of 6 digits, according to the table below. All digits in the last group of 6 digits are encoded using a single pattern RRRRRR, the one also used for UPC.
If the first digit is zero, all digits in the first group of 6 are encoded using the pattern LLLLLL used for UPC, therefore, a UPC barcode is also an EAN-13 barcode with the first digit set to zero.
First digitFirst group of 6 digitsLast group of 6 digits
0LLLLLLRRRRRR
1LLGLGGRRRRRR
2LLGGLGRRRRRR
3LLGGGLRRRRRR
4LGLLGGRRRRRR
5LGGLLGRRRRRR
6LGGGLLRRRRRR
7LGLGLGRRRRRR
8LGLGGLRRRRRR
9LGGLGLRRRRRR

This encoding guarantees that the first group always starts with an L-code, which has odd parity, and that the second group always starts with an R-code, which has even parity. Thus, it does not matter whether the barcode is scanned from the left or from the right, as the scanning software can use this parity to identify the start and end of the code.
EAN-8 barcodes encode all digits directly, using this scheme:
First group of 4 digitsLast group of 4 digits
LLLLRRRR

DigitL-codeG-codeR-code
0000110101001111110010
1001100101100111100110
2001001100110111101100
3011110101000011000010
4010001100111011011100
5011000101110011001110
6010111100001011010000
7011101100100011000100
8011011100010011001000
9000101100101111110100

Note: Entries in the R-column are bitwise complements of the respective entries in the L-column. Entries in the G-column are the entries in the R-column in reverse bit order. See pictures of all codes against a colored background.
A run of one or more black areas is known as a "bar", and a run of one or more white areas is known as a "space". As can be seen in the table, each digit's encoding comprises two bars and two spaces, and the maximum width of a bar or space is four areas.

EAN-13 barcode example

The complete EAN-13 code is thus: 4 003994 155486.

Decoding

By using the barcode center marker, it is possible for a barcode scanner to scan just one half of the barcode at a time. This allows reconstruction of the code by means of a helical scan of the barcode by an angle of approximately 45 degrees.

Japanese Article Number

Japanese Article Number is a barcode standard compatible with the EAN. Use of the JAN standard began in 1978. Originally, JAN was issued a flag code of 49. In 1992, JAN was newly issued an additional flag code of 45. In January 2001 the manufacturer code changed to 7 digits for new companies.