Home / GS1-128 & application identifiers (AIs) explained

GS1-128 & application identifiers (AIs) explained

GS1-128 is the standard barcode of the supply chain. It packs several standardized data fields – the application identifiers (AIs) – into a single code, making it self-describing.

What is GS1-128?

GS1-128 is based on Code 128 but uses a special FNC1 character and GS1 data identifiers. Create one with the GS1-128 generator.

Application identifiers (AIs)

An AI is a prefix in brackets that defines the meaning of the following data: (01) GTIN, (10) batch number, (17) expiry date (YYMMDD), (21) serial number, (37) quantity. This tells every system what the digits mean.

FNC1 & field separation

The FNC1 character marks the start and separates variable-length fields. Fixed-length fields (e.g. GTIN, expiry) need no separator, variable ones (e.g. batch) do.

Typical uses

GS1-128 marks shipping units, pallets and cases with batch, quantity and shelf life – the basis for traceability in retail, food and pharma.

Difference to EAN/ITF-14

While EAN-13 carries only a GTIN and ITF-14 marks the outer case, GS1-128 carries several data fields at once.

Related generators

FAQ

What does the number in brackets mean?

That is the application identifier (AI). It defines the meaning of the following data, e.g. (17) for the expiry date.

Is GS1-128 the same as Code 128?

GS1-128 uses the Code 128 symbology but adds FNC1 and the standardized GS1 data identifiers.

What do I need GS1-128 for?

For logistics and traceability: when a code should carry more than just the GTIN, such as batch, quantity and best-before date.