A GLN is a string of 13 digits that is globally unique. A GLN is generated by combining the following three components in left-to-right order:
GS1 Company Prefix: A globally unique number assigned to a company/organization by GS1 US to serve as the foundation for generating GS1 identifiers including GLNs. (See Section 2.4.) The GS1 Company Prefix is between 6 and 11 digits; the shorter the GS1 Company Prefix, the longer the location reference (below) and therefore the greater number of GLNs that may be allocated.
Location< Reference: A number assigned by the holder of the GS1 Company Prefix to uniquely identify a legal entity, functional entity, or physical location. This segment is the “serial” part that is assigned one-by-one by the company to create a globally unique GLN for each entity or location. The number of digits in the Location Reference varies in length depending on the length of the GS1 Company Prefix, so that the total number of digits in the GLN is 13.
Check Digit: A single digit computed from the previous 12 digits according to the GS1 check digit calculator.