What is Peppol BIS Billing 3.0?
Short answer
Peppol BIS Billing 3.0 is a rule and data specification for electronic invoices and credit notes (Credit Notes) in the Peppol network. It determines which data the document should contain, how they are written in the UBL 2.1 syntax, and which validation rules (Schematron, above EN 16931) the document must meet. It does not publish its own separate XSD schema — it uses the existing syntax base OASIS UBL 2.1. The Slovak solution adds its own transpositions and validation rules.
What must sit
For example, identifiers, dates, amounts, VAT recapitulation, currency and bindings between rows and totals.
Where is it in XML
The document is technically written in UBL 2.1 syntax — BIS rules are mapped to its elements and paths.
Why does the invoice fail?
Even a visually correct invoice may not pass if it does not meet EN 16931, Peppol BIS or Slovak transposition/validation rules.
Slovak transpositions and TDD
The Slovak solution is based on Peppol BIS Billing 3.0 and adds its own transpositions, validation rules and a link to the reporting of data (Tax Data Document) to the financial report. In practice, this Slovak specification is also informally abbreviated as "SK CIUS", the exact official name of the document is Transposition of the Peppol BIS standard under the conditions of Slovak legislation.
Conclusion
OpenPeppol — Peppol BIS Billing 3.0 · Financial Administration — Slovak transpositions and validation materials
Not legal advice. Machine-translated answer, not yet manually reviewed. For the exact wording, see the Slovak original.