12.2.   IDENTIFICATION OF GLOBAL LOCATION NUMBERS (GLN)
How can my company receive a Global Location Number (GLN) for its premises?
For an answer to this question, look into the website presented below.

GLN (Global Location Number)

As the name implies, the GLN is the GS1 Identification Key for Locations. The GLN can be used to identify physical locations and legal entities where is a need to retrieve pre-defined information to improve the efficiency of communication with the supply-chain. Global Location Numbers are a prerequiste for GS1 eCom message or to access information from the Global Data Synchronisation Network.
For help implementing GLNs, visit our GLN Allocation Rules.
The GLN is constructed as follows:

GLN Extensions

Global Location Numbers may also use an optional extension component using the Application Identifier (254) to support is restricted for internal purposes. Although optional, when used AI (254) must be in conjunction with AI (414) Identification of a physical location and can be encoded using an EPC tag, a GS1-128 symbol or a GS1 DataBar symbol.

The GLN Extension will not be communicated with trading partners except by mutual agreement and has been developed in expectation that it will be an important business requirement with the EPC Network. Locations that currently have a GLN may also use an optional GLN Extension component to distinguish unique locations (storage slots, door locations, bin storage, shelves, peg holes, rack, cabinet, computer/communication bays, etc.). However, a company may choose to assign a unique GLN, without an Extension component, as a way to identify these locations.
For a more detailed overview on the benefits of GLN see GLN Executive Summary.