EPCIS Rejection Errors: GLN Issues Before DSCSA Deadline

GLN Errors Are Causing EPCIS Rejections: What Wholesalers Need to Know Before DSCSA Deadline

Wholesale drug distributors are experiencing EPCIS file rejections due to malformed or unregistered Global Location Numbers (GLNs), jeopardizing compliance with DSCSA enhanced drug distribution security requirements that begin enforcement on November 27, 2025. The rejections stem from GLNs that do not match GS1 registry records, contain formatting errors, or reference inactive business locations.

Regulatory Background

The Drug Supply Chain Security Act (DSCSA), enacted under Title II of the Drug Quality and Security Act (Public Law 113-54), establishes national standards for tracking prescription drugs through the supply chain. Under 21 CFR 582.20, wholesale drug distributors must provide Transaction Information (TI), Transaction History (TH), and Transaction Statement (TS) in an interoperable electronic format by November 27, 2025.

The FDA adopted GS1 standards for serialized product identifiers and location identifiers. Electronic Product Code Information Services (EPCIS) files transmit transaction data between trading partners. Each EPCIS file must include valid GLNs to identify the source and destination of a drug shipment. A GLN is a 13-digit GS1 identifier that uniquely identifies a legal entity or physical location within the pharmaceutical supply chain.

FDA guidance document "Product Identifiers Under the Drug Supply Chain Security Act Questions and Answers" (revised June 2018) states: "Trading partners must use standardized numerical identifiers (SNIs) that are GS1-compliant to meet DSCSA requirements." This includes GLNs for location identification in EPCIS transaction records.

What Is Causing EPCIS Rejections

EPCIS file rejections tied to GLN errors fall into four categories:

1. Unregistered GLNs: The GLN exists in the distributor's system but is not registered with GS1 or has been deactivated in the GS1 registry. Validation systems reject files containing GLNs that return no match when queried against GS1 databases.

1. Format violations: GLNs must be exactly 13 numeric digits. Files containing GLNs with alphabetic characters, fewer than 13 digits (often due to leading zeros being stripped), or embedded spaces fail schema validation before reaching trading partner systems.

1. Location mismatches: A GLN registered to a corporate headquarters address is used in an EPCIS file to identify a warehouse or distribution center. The receiving system's validation logic flags the geographic inconsistency and rejects the file.

1. Check digit errors: The 13th digit of a GLN is a calculated check digit derived from the first 12 digits using the GS1 algorithm. Manual GLN entry or database migration errors produce invalid check digits that fail automated validation.

Trading partner Verification Router Services (VRS) systems—mandated by DSCSA for verifying product identifiers and transaction data—perform GLN validation as part of EPCIS file processing. A single invalid GLN in a batch file causes rejection of the entire file, blocking the transfer of TI/TH/TS for all products in that shipment.

Impact on Wholesale Drug Distributors

The operational consequences of GLN-related EPCIS rejections include:

Shipment holds: Product cannot move to the next trading partner until transaction data is accepted. Rejected EPCIS files create physical inventory backlogs at distribution centers while IT teams diagnose and resubmit corrected files.

Compliance documentation gaps: Under 21 CFR 582.20(b), wholesale drug distributors must receive TI/TH/TS before accepting ownership of product. If EPCIS files are rejected, the receiving distributor cannot document compliance with this requirement. This creates audit risk even if product physically arrived.

Manual remediation costs: Each rejection requires root cause analysis—reviewing GLN registration status in GS1 registries, cross-checking against internal master data, and coordinating corrections with ERP or serialization system administrators. For distributors handling hundreds of transactions daily, GLN remediation can consume significant QA resources.

Trading partner relationship strain: Repeated EPCIS rejections signal system immaturity or poor data governance. Large manufacturers and pharmacy chains are prioritizing trading partners with demonstrated EPCIS file acceptance rates above 95%. Distributors with persistent GLN errors risk being deprioritized in supply allocations, particularly for high-value specialty products.

The November 27, 2025 deadline eliminates the current paper-based fallback. Distributors that cannot reliably exchange EPCIS files due to GLN issues will be unable to receive or ship DSCSA-covered products.

What ColdChainCheck Data Shows

ColdChainCheck tracks 1,275 wholesale drug distributors and 3PLs across 51 jurisdictions. Of these entities, 1,234 hold active FDA registration—a prerequisite for DSCSA compliance but not a predictor of EPCIS readiness. FDA registration does not verify GLN registration status or EPCIS file format accuracy.

The average compliance score across tracked entities is 51/100, placing the majority in the "Fair" tier. This score reflects static compliance signals—state licenses, NABP accreditation, FDA registration—but does not capture operational readiness for EPCIS exchange. Only 63 entities (4.9%) hold NABP accreditation, which requires annual on-site inspections including review of serialization and track-and-trace capabilities. Accredited entities are statistically more likely to have mature EPCIS systems and validated GLN master data.

The compliance score distribution shows 28 entities (2.2%) in the "Excellent" tier (76-100 points) and 281 entities (22%) in the "Good" tier (61-75 points). These tiers indicate multi-state licensure and federal registration but do not confirm EPCIS testing with trading partners. The 919 entities (72%) in the "Fair" tier represent limited geographic licensure or missing data points—signals that correlate with smaller operational scale and potentially less-developed serialization infrastructure.

Practical Guidance for QA and Compliance Teams

Verify your trading partners' GLN registration status before November 27, 2025: Use the ColdChainCheck directory to identify entities in your supply chain. Cross-reference each entity's business address against their GLN record in the GS1 registry. Mismatches between ColdChainCheck's registered business location and the GLN's registered location flag potential EPCIS rejection risk.

Prioritize EPCIS testing with high-volume trading partners: Focus integration testing on the 20% of partners that represent 80% of transaction volume. Entities with NABP accreditation (visible in ColdChainCheck profiles) have demonstrated system validation to third-party auditors and are lower-risk testing candidates.

Document GLN validation as part of trading partner qualification: Add "GS1 GLN verification" as a qualification checklist item. Request proof of active GLN registration for each ship-from and ship-to location the partner will use in EPCIS files. Trading partners that cannot produce this documentation by Q3 2025 represent elevated compliance risk.

Monitor for enforcement actions related to EPCIS failures: ColdChainCheck tracks FDA warning letters and recalls. As DSCSA enforcement begins, entities that fail to meet EPCIS requirements may receive FDA Form 483 observations or warning letters. These signals will appear in entity compliance profiles and affect overall scores.

Related coverage on DSCSA serialization requirements and trading partner due diligence is available in the ColdChainCheck compliance guides.

Disclaimer: This article provides informational analysis of DSCSA requirements and EPCIS rejection patterns based on publicly available regulatory guidance. It is not legal or compliance advice. Consult your legal counsel and quality assurance team to verify trading partner compliance with 21 CFR 582 and GS1 standards.