File is not readable XML
The file cannot be read as XML – it is incomplete, damaged or not an e-invoice at all.
What to do now
Who has to fix this?
The issuer or their software has to fix this. Such files are technically defective and cannot be rescued by reworking individual fields.
Where this rule comes from
These findings arise before the actual business rules can be checked at all — for example when the XML file is not well-formed, does not match the schema, or a ZUGFeRD PDF contains no embedded XML.
- Rule ID
- FORMAT-XML
- Rule set
- File and structure errors
- Checked for
- XRechnung, ZUGFeRD, Factur-X, Peppol BIS and other EN 16931 formats
- Consequence of a violation
- The invoice is considered non-compliant with the standard and is automatically rejected by many recipients.
Does FORMAT-XML occur in your invoice?
Upload the XRechnung or the ZUGFeRD/Factur-X PDF – the validator shows every violation with the same explanation as here. Free, no login, nothing stored.
Validate your invoice nowGeneral information, not tax or legal advice. As of October 2026. Validation rules: CEN/TC 434 (EN 16931, EUPL 1.2), KoSIT (XRechnung, Apache 2.0), FNFE-MPE/FeRD (Factur-X/ZUGFeRD, Apache 2.0), OpenPeppol AISBL (Peppol BIS), ANAF (CIUS-RO). Explanations: Billvox. Licence notices