A Practical Guide to GLN Assignment, Management, and DSCSA Readiness
As DSCSA enforcement moves the pharmaceutical industry toward fully serialized, interoperable data exchange, pharmacies must ensure they are using Global Location Numbers (GLNs) correctly and consistently. Whether a pharmacy is dispensing, receiving, or participating in EPCIS data exchange with trading partners, having properly assigned and well-managed GLNs is essential for accurate tracing and compliance.
This guide explains how pharmacies can obtain GLNs, how many they need, and the best practices for managing them across a store, chain, or network.
How to Obtain a GLN
Getting a GS1 Company Prefix
A pharmacy’s GLNs originate from its GS1 Company Prefix, a unique identifier licensed directly from GS1. This prefix forms the foundation for creating GLNs, GTINs, and other GS1 identifiers used across the supply chain.
To obtain a prefix:
- Visit GS1 US and apply for a company prefix license.
- Provide basic business information, including legal entity details.
- Choose the appropriate prefix capacity based on how many identifiers you expect to create.
Once the prefix is assigned, the organization can generate as many GLNs as needed within that prefix range.
GLN Assignment Rules
GS1 requires that GLNs remain:
- Unique (each GLN must represent one and only one location or function)
- Persistent (a GLN should not change unless the location itself fundamentally changes)
- Accurate (the assigned GLN must reflect the real operational role of the location)
A GLN may represent a:
- Legal entity (the corporate organization)
- Store or pharmacy location
- Department or functional area (e.g., receiving, billing, returns)
- Digital location (e.g., EPCIS repository or data exchange endpoint)
The key rule:
If something changes in a way that affects trading partner understanding—ownership, function, or physical location—you must assign a new GLN.
How Many GLNs a Pharmacy or Network Needs
The number of GLNs needed depends on operational complexity.
A single independent pharmacy may need:
- Optional: functional GLNs (receiving, billing, etc.) if trading partners require them
A regional or national chain may require:
- 1 Corporate Legal Entity GLN
- One GLN per store or dispensing location
- Functional GLNs for departments such as centralized billing, specialty pharmacy services, mail-order or fulfillment centers, and returns management
The more locations and internal functions a business has, the more GLNs are needed to accurately represent its supply chain footprint.
Cost Considerations and Subscription Requirements
GLNs are created from your GS1 Company Prefix, which requires an annual subscription. Costs depend on:
- The size of the prefix (how many identifiers you need)
- GS1’s annual renewal requirements
There is no separate fee per GLN—once you have a prefix, you can generate GLNs as required.
However, failing to renew your GS1 subscription can invalidate your identifiers, causing compliance issues and trading partner data mismatches.
Best Practices for Pharmacies
Accurate GLN management is essential for DSCSA compliance and EPCIS interoperability. These best practices help ensure clean, reliable, and predictable GLN usage.
Naming Conventions
Pharmacies should maintain a consistent naming system to clearly distinguish different types of GLNs.
Examples:
- Legal Entity: “ABC Pharmacy Inc.”
- Store Location: “ABC Pharmacy #142 – Orlando, FL”
- Receiving Department: “ABC Pharmacy #142 – Receiving”
Clear naming prevents internal confusion and supports smooth onboarding with manufacturers and wholesalers.
Managing GLN Hierarchies
Every pharmacy organization should maintain a documented hierarchy showing how GLNs relate to each other:
- Corporate legal entity -> Store locations -> Functional departments
A hierarchy ensures:
- EPCIS data is mapped correctly
- Trading partners understand which GLN belongs where
- Changes (such as store relocations) are communicated accurately
For multi-store chains, hierarchy management is essential for avoiding duplicated or inconsistent GLN assignments across different regions.
Avoiding Duplicate or Stale GLNs
Common GLN problems include:
- Re-using old GLNs after a store closure or relocation
- Accidentally assigning two GLNs to the same physical location
- Using a GLN that no longer reflects the true purpose of the location
To avoid issues:
- Maintain a master GLN registry
- Review assignments annually
- Align GLNs with real-world operations whenever changes occur
Incorrect or stale GLNs are a leading cause of EPCIS mismatches and DSCSA compliance delays.
When to Retire or Reassign a GLN
A GLN should be retired when the location or function it identifies is permanently changed in a way that affects trading partner understanding.
Examples requiring a new GLN:
- A store relocates to a new address
- A receiving department moves or is restructured
- A legal entity changes ownership or is merged
- A location closes permanently
A GLN should not be reused for a new purpose once retired. Reuse creates ambiguity and can cause EPCIS failures.
Summary
Obtaining a GLN is straightforward, but managing GLNs correctly is essential for DSCSA compliance and accurate EPCIS data exchange. Pharmacies must understand how to obtain GLNs, determine how many they need, and maintain clean hierarchies that reflect real operations.
With proper processes in place—naming standards, hierarchy management, retirement rules, and a clear GLN registry—pharmacies can avoid errors, prevent data mismatches, and support seamless traceability across the supply chain.
Want to learn more about GLNs? Explore the related articles in our blog series to dive deeper into how GLNs work, why they matter, and how they’re used across the supply chain.
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