GLN Requirements for Outbound EPCIS

Ensuring Accurate Location Data for Wholesalers and Manufacturers Under DSCSA

As DSCSA enforcement approaches, wholesalers and manufacturers must generate outbound EPCIS files that accurately represent serialized product movements. A central part of this accuracy is the correct use of Global Location Numbers (GLNs).

Across DSCSA pilots and interoperability testing, GLN inconsistencies have emerged as one of the most common causes of EPCIS rejections. Understanding which GLNs are required in outbound files—and how mismatches impact trading partners—is essential for a smooth, compliant data exchange process.

Mandatory vs. Optional GLN Fields in Outbound EPCIS

EPCIS events include several fields where GLNs may appear. Some are required for all outbound DSCSA events, while others apply only in specific scenarios.

Mandatory GLN Fields

1. bizLocation

Identifies the business location responsible for the serialized event.
For wholesalers and manufacturers, this may be:

• A distribution center

• A packaging or manufacturing site

• A corporate operational unit

The GLN must be current, valid, and recognized by the receiving trading partner.

2. readPoint

Required for events involving physical handling, such as:

• Shipping

• Receiving

• Packing

• Aggregation or disaggregation

The readPoint GLN represents the specific physical location—such as a shipping dock or receiving bay—where the event occurred.

3. Trading Partner GLNs in Transactional Context

Outbound EPCIS files may reference trading partner GLNs for:

• Ship-to

• Bill-to

• Receiving location

• Trading partner legal entity

Any mismatched or outdated partner GLN will typically cause an EPCIS rejection.

Optional or Conditional GLN Fields

Some GLN fields appear only in certain EPCIS implementations or event types:

• Source/Destination lists

• Functional or department-level GLNs

• Operational sub-location identifiers

When optional GLNs are used, they must still represent correct, official identifiers.

How Mismatched GLNs Cause EPCIS Rejections

Trading partners depend on consistent GLNs to correctly map serialized events to real-world locations. When GLNs do not match across systems, outbound EPCIS files often fail validation.

1. Multiple GLNs for the Same Location

If a partner has several GLNs on file for the same facility—common in legacy onboarding—your EPCIS file may reference a version they no longer use.

Result: The partner cannot match the event → EPCIS rejection.

2. Incorrect GLN Type in a Required Field

Examples include:

• Using a corporate GLN where a distribution center GLN is required

• Using a billing GLN in a ship-to field

• Using a legal entity GLN instead of a physical location GLN

Result: Ambiguous or invalid EPCIS event data → partner rejects the file.

3. Outdated GLNs After Relocations or Acquisitions

If a location has changed, consolidated, or closed, stale GLNs can remain in partner systems.

Result: Event data is linked to the wrong location → failed alignment.

4. Unofficial or Partner-Created GLNs

Some organizations historically assigned GLNs on behalf of partners during onboarding or EDI setup.
Under DSCSA, partners must use official GS1-issued GLNs.

Result: EPCIS system flags the GLN as unknown → file rejected.

Summary

Accurate GLN usage is essential for valid outbound EPCIS files and DSCSA interoperability. Wholesalers and manufacturers should ensure:

• Mandatory fields like bizLocation and readPoint contain correct, official GLNs

• Trading partner GLNs are current and verified

• Outdated, duplicate, or unofficial GLNs are removed from use

• GLN alignment is checked early during interoperability testing

Correct GLN management greatly reduces EPCIS rejections and supports consistent, compliant traceability across all trading partners.

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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.

• Introduction to GLNs: The Foundation of Global Track-and-Trace, DSCSA Compliance, and EPCIS Data Exchange
• How GLNs Are Used in DSCSA & EPCIS: Why Every Pharmacy Needs Accurate Location Data
• GLN Structure Explained: How the 13-Digit Identifier Powers DSCSA Compliance and EPCIS Traceability
• ‍How to Obtain a GLN and Best Practices for Pharmacies
• Common GLN Mistakes (and How to Avoid Them)