Encoding GTIN-14s into GS1-128 Barcodes

GTIN describes a family of GS1 global data structures that employs 14 digits in various data carriers. A GTIN-14 is a 14 digit number used to identify trade items at various packaging levels. The barcode encoding of the GTIN-14 is commonly within an ITF-14 barcode (i.e. case code), but many industry and applications use GS1-128 for encoding GTIN-14s. The GS1-128 barcode allows other data to be included such as; best before dates, Batch / Lot numbers, and case weight.

GTIN-14 with additional fields (Expiration, Lot)

Encoding GTIN-14s

  • Application Identifier – The AI (01) is used when the data field contains a GTIN.
  •  Indicator Digit – The indicator digit denotes the level of packaging for a particular carton. A number 0 – 8 should be used as the indicator digit. *This is a general practice please call if additional assistance is needed.
  • GS1 Company Prefix – The GS1 Company Prefix is a 7-10 digit number assigned by GS1 to uniquely identify ownership of a particular brand.
  • Item Reference – For cartons that contain the same item the item reference is the same as that used for the item level GTIN (GTIN-8, GTIN-12, GTIN-13).  For cartons that contain an assortment of items a new item referenced is assigned.
  • Check Digit – The last digit of the GTIN-14 is a calculated check digit. Using a MOD10 check digit algorithm, the calculated check digit prevents substitution errors.
  • Optional Data – Additional data along with the appropriate GS1 Application Identifier may also be encoded.

Creating & Printing GS1-128 Barcodes

Verifying GS1-128 Barcodes