GS1 & Barcodes

GS1-logo GS1 is the only organization that is able to assign a GTIN code to a manufacturer. It is a worldwide network of GS1 Member Organisations (MO) covering 150 countries (see map below).

This non-profit organization, founded in the 1970s in the United States, is governed and supported by almost all manufacturers in the world (1.2 million worldwide, 32,000 in France).

Its objective is to provide standards and to optimize supply chain processes.


For more information on GS1, please visit their website


A GTIN (Global Trade Item Number) is assigned to a product by GS1. This is a code identifying any business unit (consumer unit or unit standard grouping …) in an international and unique way.

The GTIN can contain 8, 12, 13 or 14 digits, and can be constructed using four structures, depending on the application:

  • GTIN-8 can be encoded in EAN-8
  • GTIN-12 can be encoded in UPC-A, ITF-14, GS1-128
  • GTIN-13 can be encoded in EAN-13, ITF-14, GS1-128
  • GTIN-14 can be encoded in ITF-14, GS1-128

Codification GTIN-12 is included in coding GTIN-13 by the addition of a 0 in the first position.

ISBN (International Standard Book Number) books, newspapers and magazines, originally composed of 10 characters, is contained within the GTIN-13 code and consists of the following sequence: 978 + number + editor + language area number book + check digit GS1.

GTIN code structure

codification-EANThe GTIN structure is decisive in terms of aproach and methodology to gather GTIN codes:

The GCP (Global Company Prefix) is the identifier of the manufacturer (‘a’ + ‘b’ in the figure). This identifier is of variable length and composed of the country code registration of the product (‘a’ in the figure) and of the GS1 registration code (‘b’ the diagram). Remark:  a is not the country of origin of the product but the country of registration.

One or more GCP are assigned to a manufacturer and they can use it to register their product with a variable length code (‘c’ in the diagram).

GTIN ends with a check digit to prevent input errors (‘d’ on the diagram).
The method of calculating the check digit is explained on the following page.

The first 3 digits of the GTIN not only give the country of registration of the product but also the length of GCP (although there may be exceptions). Below is a table extracted from (Source) with added elements on orange background.

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