What is a GTIN-14?
A GTIN-14 identifies a trade unit rather than a consumer item: the case of 12 bottles, the carton of 48 bars, the layer of a pallet. Shops never scan it at the till - warehouses, distribution centres and the ordering systems between manufacturer and retailer do.
How a GTIN-14 is built
- Indicator digit (1 digit) - tells packaging levels of the same product apart.
- The first twelve digits of the contained item's GTIN-13 - GS1 company prefix and item reference, without the old check digit.
- Check digit - recalculated over all thirteen digits before it, with the same GS1 modulo 10 rule as EAN-13 and UPC.
Example: the item has the GTIN-13 4006381333931. A case of it with indicator 1 gets 1 400638133393 plus a new check digit - the last digit changes because the indicator now takes part in the sum.
What the indicator digit means
1 to 8 are free for packaging levels. They carry no fixed meaning: 1 is not "inner pack" by rule, the brand owner simply uses a different indicator for each level of the same product. 0 means the number is an ordinary GTIN-13, GTIN-12 or GTIN-8 padded with leading zeros to fourteen digits - that is how retail codes are stored in fourteen digit database fields. 9 marks variable measure items, goods traded by weight or length. This generator therefore offers 1 to 8 only.
A brand owner may also give a case its own GTIN-13 instead. Both are valid ways to number a trade unit; the indicator variant keeps the relation to the contained item visible in the number.
ITF-14, GS1-128 and case codes
On corrugated cartons a GTIN-14 is usually printed as an ITF-14 barcode: Interleaved 2 of 5, a symbol that prints legibly on rough cardboard and is framed by a thick bearer bar. That is why the number is often called a case code or ITF-14 number.
In a GS1-128 label or a GS1 DataMatrix the same number appears behind the application identifier (01), often next to a batch number, a best before date or a quantity. Application identifier (01) always holds fourteen digits - a GTIN-13 written there gets a leading 0, which is the indicator 0 described above.
What the numbers on this page are for
They are test data: structurally valid, registered to nobody. Use them to test a warehouse system, an EDI message, a GS1-128 label layout or a scanner configuration that must accept fourteen digit codes. A real case code is derived from your own product's GTIN, which comes with a licence from your GS1 member organisation.