May be XML invoice technically correct, but commercially wrong?
Short answer
Yes. An electronic invoice may undergo all technical checks and may nevertheless contain incorrect data. Simply put: The system can confirm that the invoice is properly created, but cannot confirm that you are billing the right thing to the right customer or at the right price.
Validation subject
The validator shall assess the data present in the electronic invoice and the rules formally defined above.
Outside validation scope
Internal registers, master data, ERP/CRM/WMS links, internal approval and accounting policies are not subject to EN 16931 or Peppol validation.
Technically accepted, internally rejected
Invoice can pass XSD, EN 16931 and Peppol BIS and yet be stopped after import by the internal rule of the recipient.
More control levels
Technical validation, profile validation, master data control, order binding and internal rules address different risks.
Conclusion
Not legal advice. Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.