POS Systems Error Code
Systems & Devices
POS Systems
30 | Format error
Industry
Systems & Devices
Canonical
/systems/pos-systems/error-codes/30/
Last Updated
Feb 27, 2026
Summary
The authorization request format was invalid or could not be parsed by the receiver.
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What This Code Means
Response code 30 indicates that the receiving system (issuer, network, or processor) could not process the request because the message format was invalid. This is often a technical/configuration issue with the terminal, gateway, or integration.
Where Users Usually See This Code
- New integrations or recently changed gateway settings
- Terminal software updates that alter field formats
- Processor logs showing message/field validation errors
Why This Code Appears
- Missing or malformed required fields
- Incorrect message type or unsupported transaction type
- Encoding/field length mismatches
What Typically Happens Next
- Transaction declines until the message format is corrected
- Processor support may request raw message logs for diagnosis
What This Code Is Not
- It is not a customer account decline reason
- It is not a “do not honor” risk decision
Troubleshooting Checklist
- □ Confirm terminal/gateway configuration matches the processor specification
- □ Review recent changes to message mapping/fields
- □ Check for updates to the payment SDK/integration
- □ Contact processor support with timestamps and transaction IDs
Notes And Edge Cases
Some systems use “format error” for multiple validation failures; extended logs are often required.
Related Codes
8 links
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