GS1-128

The GS1-128 standard is an application standard within the Code 128 barcode. It identifies data with Application Identifiers (AI). Without spaces below, a simple SSCC (Serial Shipping Container Code) barcode would look something like this:

[FNC1] 00 12345678 0000000001

In the example above, [FNC1] is the single character Function Code 1, which specifies that a Code 128 barcode is a GS1-128 code. 00 is the serial shipping container code ("SSCC") AI that designates the following data as a serial shipping container code. 12345678 is the company number. 0000000001 is the container number.

It is possible to encode several pieces of data in one barcode. For example, a product serial number (application identifier code 21), production date (code 11), and expiration date (code 17) together would look something like this:

[FNC1] 21 12345 [FNC1] 11 090101 17 100101

An additional FNC1 is required before the production date, because the preceding product serial number is variable length. This is not required before the expiration date, because the production date is fixed length. Reordering the components to place a variable-length field last produces a more compact form:

[FNC1] 11 090101 17 100101 21 12345

This list is from 2003 and therefore out of date and possibly incorrect. Also this is copyrighted by GS1 – for the up to date list please see the link below for the GS1 General Specifications[2] Because code 128 is more efficient at coding pairs of digits, preference is given to even lengths in numeric fields.

All dates are formatted as YYMMDD.

y in the AI gives a number of decimal places in the following value. The represented value is the following integer divided by 10^y. For example, a net weight of 22.7 kg could be coded as 3101 000227, 3102 002270, 3103 022700, or 3104 227000.

• Informational site for GS1-128 symbology