How do I verify that the XML invoice is correct?
Short answer
One green check is not enough. An XML invoice may be technically correctly created, but may not meet the rules of EN 16931. It may meet EN 16931, but violate the additional rules of Peppol BIS Billing or Slovak requirements. And also a document
XML structure
It verifies the structure, order of elements, data types and mandatory elements according to the UBL 2.1 scheme. If the XML does not pass the XSD, further checks cannot be continued.
Business significance
Checks mandatory business data, logical links, calculations, VAT and mandatory identifiers — via Schematron rules.
Network rules
Peppol Additional Rules: Supported Codes, Allowed Values, Party IDs, EndpointIDs and Email Addresses.
National requirements
Slovak validation rules beyond the framework of the European standard — e.g. method of stating VAT number/ID (scheme 0245).
Conclusion
The correctness of the XML invoice cannot be confirmed by a single green check.
Act No. 222/2004 Z. z. Coll. about VAT · FAQ of the Financial Administration of the Slovak Republic from 7 July 2026 · Peppol BIS Billing 3.0
Not legal advice. Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.