When internal to an organisation, sub-locations may be identified by a GLN or by a GLN with a GLN extension component.
GLN SHALL be used in open value chains where the complete set of trading partners is not known in advance and may change over time.
GLN with GLN extension component may be exchanged, by mutual agreement, between two or more parties when the standard being used supports GLN extension component.
This means that companies must confirm that their internal systems and the external systems expected to interact with the GLN extension components are able to receive and process information related to the physical location identified by a GLN and the sub-location identified by a GLN extension component through interoperable means.
Important: A GLN extension component SHALL only be used in conjunction with a GLN identifying a physical location. While a single GLN may be used to identify a party and separately to identify a location, a GLN extension component SHALL only be associated with the physical location.