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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Guides

POS Terminal Error Codes: Payment Processing, Connectivity, and Device Health

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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

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