The Global Language of Business

GTIN Types

The GTIN is a number used to uniquely identify trade items worldwide. The GTIN is most commonly used to identify consumer products and outer cases.There are a range of different GTIN types to cater for different product and item types.

Fixed Weight Products

Fixed Weight Consumer Units are products which are intended to cross the retail point of sale and are usually identified with one of three GTINs.

The most common GTIN is the GTIN 13, with a GTIN 8 being used on products which are too small for a full GS1 13 bar code symbol. Consumer Units for sale in the United States or Canada previously could only be marked with a UCC 12 number.  Now products going to the US or Canada can be marked with an 8,12 or 13 digit number.  

  • GTIN 13: a 13 digit number typically used to identify consumer units that will be scanned at the point of sale.  GTIN 13 numbers are typically generated from a Global Company Prefix (GCP) which has been licenced to you.  Different prefixes are allocated to your company for fixed weight and variable weight products.   
  • GTIN 8: an 8 digit number for very small fixed weight consumer products. GTIN  8s are allocated on a one by one basis by GS1 Ireland to a specific product.  Certain criteria relating to the size of the printable area on the product must be met in order to qualify for an GTIN 8. 
  • GTIN 12 or UCC 12: a 12 digit number for fixed weight consumer units sold in the United States & Canada (The EAN 13 is now accepted in the US and Canada)
  • UCC 8: an 8 digit number created from a UCC 12 via a process called zero supression.  These numbers are used on small fixed weight consumer units sold in the United States & Canada (The GTIN 8 is now accepted in the US and Canada)
  • GTIN 14: a 14 digit number for traded items or outer cases.

Variable Weight Products

The term Variable Measure Trade Item is used to describe products which are sold, ordered or produced in quantities which can vary continuously, such as fruit and vegetables, meat, cheese, rope, chain, fabric, carpets on a roll, etc.

For Retail Variable Measure Items the price must be included in the bar code to be read at the checkout.  In the current family of GS1 Symbols, there is no room to accommodate both a full 13 digit GTIN and the price, so a shorter number must be used to identify the product.

Variable Weight products may be identified with a 20 prefix if they are pre packed branded goods.  An instore variable weight product code commencing with a 02 prefix may be used by retailers in their weighing scales for loose produce such as fruit and vegetables or for products served at the meat or cheese counters.

Traded Units

Traded Unit is the term used to define a product or case of product exchanged between two trading partners.  Traded units are commonly known as outer cases and the bar codes used are usually called outer bar codes.  An outer case code is typically 14 digits long and is allocated from the standard bank of numbers allocated to your company.  To generate a GTIN 14 or outer case code simply allocate a new 12 digit number from your number bank as outlined in the section above.

  • If the traded unit or outer case you wish to identify contains fixed weight consumer units, prefix your new 12 digit number with 0 and then calculate the check digit in the standard way.
  • If the outer case contains variable weight consumer units, prefix the new 12 digit number with the digit 9 and then calculate the check digit.

This fourteen digit number may now be printed as either an ITF 14 or GS1 128 bar code symbol.

Publications (ISSN) & (ISBN)

Two numbering structures are utilised to identify publications. The first is an ISSN (International Standard Serial Number) and the second is an ISBN (International Standard Book Number).

An ISSN is allocated to serials i.e. a publication issued in successive parts and intended to be continued indefinitely. Serials include periodicals, magazines, newspapers, annuals, journals etc. The ISSN is an internationally used code which uniquely identifies a title (thereby distinguishing it from any other publications with the same title). It is an eight-digit number, in two groups of four digits, separated by a hyphen and preceded by the letters ISSN (and a space), e.g.:ISSN 0332-0006. The GS1 prefix 977 is used to encode an ISSN into an EAN 13 bar code.

Please Note: GS1 Ireland does not manage the allocation of numbers for publications. All enquiries relating to numbers and the legal deposit requirement of the Copyright Act 1963 should be directed to:

Irish ISSN Centre
National Library of Ireland
Kildare Street
Dublin 2.
Tel: 353 1 6030351
Fax: 353 1 6030289

Books are identified with a 10 digit ISBN consisting of a prefix, which indicates the Centre that assigned it, followed by a string of digits assigned by the Centre to identify the publisher, followed by the digit or digits which identify the specific item. The final digit is a check digit. The GS1 prefix 978 is used to encode an ISBN into an EAN 13 bar code symbol.

ISBNs are allocated by:
The ISBN Agency, 3rd Floor, Midas House, 62 Goldsworth Road, Woking, Surrey, GU21 6LQ England.
Tel: + 44 (0) 1483 712 215 (9.00am to 5.00pm).
Fax: + 44 (0) 1483 712 214