Drop your XML invoice here
or click to browse your files
No invoice to test with?
Try with a sample Peppol BIS 3.0 invoice — see results instantly
Drop your XML invoice here
or click to browse your files
No invoice to test with?
Try with a sample Peppol BIS 3.0 invoice — see results instantly
KSeF (Krajowy System e-Faktur) is Poland's National e-Invoice System, mandatory for all B2B transactions from February 2026. Invoices must be submitted as structured XML in the FA(3) schema format. The system validates, timestamps, and assigns a unique KSeF ID to each invoice.
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Full VAT invoice with all mandatory fields per FA(3) schema
Use case: Standard B2B transactions — the most common invoice type in KSeF
Correction of a previously issued invoice
Use case: Adjustments to amounts, quantities, or VAT rates on existing invoices
Invoice for advance or partial payments received
Use case: Documenting prepayments before goods or services are delivered
Pre-submission FA(3) schema check. Validates NIP format, mandatory fields, date rules, and calculation consistency. Catch errors before KSeF rejects your invoice.
KSeF rejects non-compliant XML immediately — only validated invoices receive a KSeF ID. Error messages reference XSD violations without fix guidance.
SAP, Comarch, and Symfonia generate FA(3) XML but may not validate all schema rules. NIP format errors and missing conditional fields pass through undetected.
System Name
Krajowy System e-Faktur
Schema Version
FA(3)
Maintained By
Ministry of Finance (Poland)
B2B Mandate
February 2026 (large), April 2026 (all)
Key Identifier
NIP (10 digits, mod-11 checksum)
100% Private Validation
All validation runs entirely in your browser. Your invoice files never leave your device and are never sent to our servers. We can't see your data even if we wanted to.