How to read XML from KSeF
Learn how to open an FA(3) XML file, find invoice data, the KSeF number, tax IDs, line items and amounts, and when to use a validator or XML-to-PDF converter.
TechnologyJune 9, 2026
Technology
KSeF technology explained: API, FA(3) XML, validation, data security, integrations and architecture for automated invoice workflows.
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KSeF and JPK: how the invoice system works with the JPK family of structures
KSeF does not replace JPK_VAT. Learn the differences between FA(3), JPK_V7M, JPK_V7K and JPK_FA, and the rules for KSeF numbers, corrections and offline modes.
TechnologyJune 6, 2026
XML and the FA(3) schema in KSeF - a guide for businesses
What XML is, why KSeF requires it, and why FA(2) no longer works in 2026. A practical guide without technical jargon.
TechnologyApril 17, 2026
XML Validation and Processing in KSeF – How the Platform Interprets an Invoice
In the KSeF system, an invoice is not a visual document but a structured XML file. Learn about the multi-step validation and parsing process that determines whether an invoice is accepted.
TechnologyMarch 16, 2026