EN 16931 Validator
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🇵🇱 Validate EN 16931 Invoices for Poland
EN 16931Mandatory
EN 16931 is required in Poland. Poland launched KSeF (Krajowy System e-Faktur) as mandatory for all B2B transactions on February 1, 2026.
Quick Facts
What We Validate
EN 16931 semantic model compliance
Business rule validation (BR-xx rules)
VAT category rules (BR-S, BR-Z, BR-E, etc.)
Calculation rules (BR-CO-xx)
Code list validation
Party identification
Cross-border requirements
Invoice Navigator covers 134 KSeF FA(3) rules for Poland.
Common EN 16931 Errors
Poland E-Invoicing Requirements
Phase
Status
Scope
KSeF voluntary
Live (Jan 2022)
All VAT payers (opt-in)
B2B mandatory — Phase 1
Live (Feb 1, 2026)
Large taxpayers (>200M PLN turnover)
B2B mandatory — Phase 2
Live (Apr 1, 2026)
All remaining VAT-registered entities (SMEs, sole proprietors, VAT-exempt businesses)
B2G
Live (Feb 1, 2026)
Included in general KSeF mandate
Financial penalties
Jan 1, 2027
Up to 100% of VAT amount on non-compliant invoices
Validation engineKSeF (centralized government validation)
Required CIUSKSeF XML schema (FA(3) — proprietary, replaced FA(2) in February 2026; not EN 16931)
Government portalKSeF (ksef.mf.gov.pl)
Routing identifierNIP (tax identification number)
PeppolNo — KSeF is a closed national system
KSeF is architecturally different from Peppol-based mandates. If you've built for Belgium or Germany, assume nothing transfers.
FAQ
What is EN 16931?
EN 16931 is the European standard for electronic invoicing. It defines a semantic data model and business rules that all EU e-invoices must follow, regardless of syntax (UBL or CII).
Is EN 16931 mandatory?
For B2G invoices to EU public sector, yes. For B2B, it depends on the country. Under ViDA (VAT in the Digital Age), EN 16931 compliance will become essential across the EU.
What syntax should I use for EN 16931?
EN 16931 supports two syntaxes: UBL 2.1 and UN/CEFACT CII. UBL is more common for Peppol; CII is used in ZUGFeRD/Factur-X. Both express the same data.
What's a CIUS?
A CIUS (Core Invoice Usage Specification) is a national adaptation of EN 16931. Examples: XRechnung (Germany), Peppol BIS (international), CIUS-RO (Romania).
How do I prepare for ViDA?
Start by ensuring your invoices comply with EN 16931. Our validator checks all the business rules that will be required under the ViDA e-invoicing mandate.
Validators
XRechnung Validator
Validators
ZUGFeRD Validator
Answers
How do you validate an e-invoice?
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