400
INVALID_INPUTThe JSON shape or one of its values is invalid.
What to do
Fix the fields listed in errors[] and send the request again.
Appears on
Every API error code across all endpoints in one searchable place — HTTP status,
code, description, and the remediation action. When you see an errorCode in a
logged response, look it up here instead of hunting through the API Reference.
Each entry links back to the endpoint(s) where it can occur.
This list is generated from the same per-endpoint error data as the API Reference, so the two views never disagree.
These are request or infrastructure failures. Validation findings from the validate endpoints are returned as 200 OK response bodies, not error codes — see the API Reference for those.
INVALID_INPUTThe JSON shape or one of its values is invalid.
What to do
Fix the fields listed in errors[] and send the request again.
Appears on
UNSUPPORTED_SPECThe selected syntax or version is not available.
What to do
Use CII or UBL and omit version to select the latest supported release.
Appears on
FIELD_REQUIREDA value needed by AUTO calculation is missing.
What to do
Add the field named in errors[].field, then retry.
Appears on
INVALID_INPUTA multipart part is missing or request JSON is malformed.
What to do
Send both file and request parts, then retry.
Appears on
MALFORMED_XMLThe uploaded file is not well-formed XML.
What to do
Repair the XML syntax before validation.
Appears on
UNSUPPORTED_SPECThe requested validation version is unavailable.
What to do
Omit version to use the latest active ruleset.
Appears on
INVALID_INPUTThe JSON shape or a field value is invalid.
What to do
Fix the fields listed in errors[] and retry.
Appears on
UNSUPPORTED_SPECThe selected syntax or version is unavailable.
What to do
Use CII or UBL and omit version for the latest release.
Appears on
INVALID_INPUTA multipart part is missing or invalid.
What to do
Send both file and request parts, then retry.
Appears on
MALFORMED_XMLThe upload is not well-formed XML.
What to do
Repair the XML syntax before validation.
Appears on
INVALID_INPUTThe JSON shape or a value is invalid. config.metadataLanguage is eligible only on this endpoint (rejected with 400 on xrechnung and en16931); unsupported codes such as "fr" or "de-DE" are also rejected here.
What to do
Fix the fields listed in errors[] and retry.
Appears on
UNSUPPORTED_SPECThe version, syntax, or profile is unavailable.
What to do
Use CII and a supported ZUGFeRD profile.
Appears on
FIELD_REQUIREDA calculation input is missing.
What to do
Add the field named in errors[].field.
Appears on
MALFORMED_PDFThe upload is not a readable ZUGFeRD PDF.
What to do
Confirm it is a PDF/A-3 with embedded invoice XML.
Appears on
XSD_VALIDATION_FAILEDThe generated XML does not match its technical schema.
What to do
Review errors[]; fix the mapped invoice fields or contact support if they were valid.
Appears on
SCHEMATRON_VALIDATION_FAILEDThe invoice breaks a business rule for the selected standard.
What to do
Use the rule code and field in errors[] to correct the invoice data.
Appears on
VALIDATION_FAILEDPost-generation validation rejected the document.
What to do
Fix every validator finding in errors[]; no document was returned.
Appears on
VALIDATION_FAILEDThe generated XML breaks EN 16931 rules.
What to do
Correct every finding in errors[] and retry.
Appears on
VALIDATION_FAILEDThe embedded XML breaks its business rules.
What to do
Correct every validator finding in errors[].
Appears on
PDF_A3_VALIDATION_FAILEDThe generated PDF container failed PDF/A-3 checks.
What to do
Contact support with X-Request-Id; this usually indicates a packaging failure.
Appears on
RATE_LIMIT_EXCEEDEDYour plan's request rate limit has been exceeded. Every authenticated request consumes one token before validation or billing.
What to do
Wait the number of seconds in the Retry-After header, then retry. The response also includes RateLimit-Limit, RateLimit-Remaining, and RateLimit-Reset headers.
GENERATION_FAILEDThe document pipeline could not complete.
What to do
Retry once. If it repeats, contact support with X-Request-Id.
Appears on
INTERNAL_ERRORAn unexpected server failure occurred.
What to do
Retry later or contact support with X-Request-Id.
GENERATION_FAILEDThe validation engine could not start.
What to do
Retry once, then contact support with X-Request-Id.
Appears on
GENERATION_FAILEDThe generation pipeline failed.
What to do
Retry once, then contact support with X-Request-Id.
Appears on
INTERNAL_ERRORThe validator failed unexpectedly.
What to do
Retry later or contact support with X-Request-Id.
Appears on
GENERATION_FAILEDThe PDF pipeline failed.
What to do
Retry once, then contact support with X-Request-Id.
Appears on
GENERATION_FAILEDThe validation pipeline could not run.
What to do
Retry once, then contact support with X-Request-Id.
Appears on
RATE_LIMIT_CONFIGURATION_UNAVAILABLEThe rate limit policy for your account could not be resolved. No invoice work was performed and no credits were charged.
What to do
Retry later. If it persists, contact support with X-Request-Id.