Common EDI Errors and How to Fix Them

Even well-designed EDI systems can fail due to data issues, partner rules, or communication problems. Understanding common EDI errors and how to fix them helps reduce downtime, chargebacks, and partner frustration. 

1. Missing or Invalid Mandatory Segments

Error:
Required segments (BEG, PO1, ST, SE, BGM, LIN, etc.) are missing or incomplete.

Reason:

• Incorrect mapping

• ERP source data missing

• Partner-specific rules ignored

How to Fix:

• Validate EDI against partner implementation guides

• Add pre-validation checks before transmission

• Ensure ERP mandatory fields are populated

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2. Incorrect Control Numbers (ISA/GS/ST)

Error:
Duplicate or out-of-sequence control numbers cause rejection.

Reason:

• Control numbers not incremented correctly

• Multiple systems sending files

• Manual file reprocessing

How to Fix:

• Centralize control number management

• Never reuse control numbers

• Reset numbers only with partner approval

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3. Segment Terminator & Delimiter Issues

Error:
Partner cannot parse the EDI file.

Reason:

• Wrong delimiters used

• Special characters in data

• Incorrect ISA settings

How to Fix:

• Confirm delimiters during partner setup

• Escape or clean special characters

• Keep ISA segment consistent

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4. Code & Qualifier Validation Failures

Error:
Invalid codes (UOM, currency, qualifiers).

Reason:

• ERP values don’t match partner code lists

• Missing code translation

How to Fix:

• Maintain code cross-reference tables

• Validate codes during mapping

• Align ERP master data with partner requirements

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5. Functional Acknowledgment (997 / CONTRL) Errors

Error:
997 shows rejection or partial acceptance.

Reason:

• Structural errors

• Missing mandatory segments

• Incorrect hierarchy

How to Fix:

• Always analyze AK3/AK4 segments

• Fix structure before resending

• Never ignore 997 rejections

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6. Trading Partner-Specific Rule Violations

Error:
File passes standard validation but fails partner checks.

Reason:

• Partner-specific mandatory fields missing

• Incorrect packaging or hierarchy

• Version mismatch

How to Fix:

• Follow partner implementation guides strictly

• Maintain partner-specific mappings

• Version control all changes

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7. Communication & Connectivity Errors

Error:
Files not sent or received.

Reason:

• AS2 certificate expired

• SFTP password changed

• Network issues

How to Fix:

• Monitor certificate expiry dates

• Automate connectivity health checks

• Maintain backup communication methods

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8. Duplicate Transactions

Error:
Same document processed multiple times.

Reason:

• Resending files without control checks

• No duplicate detection logic

How to Fix:

• Use control numbers & document IDs

• Implement duplicate detection

• Confirm partner receipt before resending

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9. Data Mismatch Between EDI & ERP

Error:
Totals, quantities, or prices don’t match.

Reason:

• Incorrect mapping logic

• Decimal or rounding issues

How to Fix:

• Reconcile ERP vs EDI data

• Apply rounding rules consistently

• Validate totals before sending

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10. Failed or Incomplete Testing

Error:
Issues appear after go-live.

Reason:

• Incomplete scenario testing

• Skipped negative testing

How to Fix:

• Test all document types

• Perform volume & negative testing

• Get partner sign-off before go-live

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Best Practices to Avoid EDI Errors

• Monitor EDI transactions daily

• Maintain strong documentation

• Automate validations and alerts

• Keep partner communication clear

• Perform periodic audits

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Summary

Most EDI errors are preventable with proper validation, monitoring, and partner alignment. A proactive approach reduces downtime, avoids penalties, and builds strong trading partner relationships.

Mastering error handling is what separates a junior EDI analyst from a senior EDI consultant.