Error Handling and Validation

The KlickTipp API uses HTTP status codes to distinguish between technical request handling and business-level validation or subscription errors.

This allows integrations to clearly separate transport and authentication issues from domain-specific subscription and validation failures.

Integrations must always evaluate both the HTTP status code and the response body.

In addition to business-level errors, the API uses standard HTTP status codes for technical and protocol-related situations.

A status code of 406 indicates that the request was syntactically valid and successfully processed by the API, but rejected due to business rules or validation constraints.

Errors related to subscription logic, contact state, validation rules, and business constraints are typically returned with HTTP status code 406.

In these cases, the request was syntactically valid and processed by the API, but rejected due to business rules or invalid data.

The response body for HTTP 406 always contains the numeric error field. Additional fields may be present depending on the error type.

The response body contains a numeric error code providing details about the failure.

The response body for HTTP 406 always contains the numeric error field. Additional fields may be present depending on the error type.

{
"error": 10,
"code": 5
}

When handling errors, first evaluate the HTTP status code and, for responses with status 406, inspect the error field and the optional code value to determine the exact cause.

Field validation errors occur when submitted values do not match the expected field type or format configured in the KlickTipp account.

Error 8 is the only error type that returns field-level validation details instead of a generic error subcode.

{
"error": 8,
"field": "LeadValue",
"name": "fieldLeadValue",
"reason": "must be a numeric value",
"field_value": "A"
}

Field validation errors indicate invalid request data and should not be retried until the payload has been corrected.

The following table lists all business-level error codes returned with HTTP status 406. These errors indicate that the request was technically valid but rejected due to subscription state, validation rules, or business constraints.

The response body for HTTP 406 always contains the numeric error field. Additional fields may be present depending on the error type.

• HTTP status = 406 and error = 8
  Validate request payload and field formats
  Retry only after correction

• HTTP status = 406 and error = 10 with subcode
  Indicates a contact update failure
  Retry may be possible depending on the subcode

• HTTP status ≠ 406
  Indicates a technical or authentication issue
  Handle independently from business logic

HTTP status codes indicate whether a request failed due to a technical issue or a business-level constraint.

Business and validation errors are returned with HTTP status 406 and include a numeric error code in the response body. The error field defines the general failure category, while the optional code field provides additional context about the exact cause.

Error 8 represents field-level validation failures and returns structured details about the affected field and the reason for rejection. Validation errors must be corrected in the request payload before retrying the request.

• Data Field Types and Input Formats
• Listbuilding API Reference
• Management API Reference