ksefuj

Generate and validate KSeF FA(3) e-invoices — Poland's mandatory structured invoice format (effective from 2026-02-01 for large companies, 2026-04-01 for all). Use this skill whenever the user asks about: issuing invoices to KSeF, FA(3) XML structure, mapping invoice data to the FA(3) schema, e-invoice validation, KSeF validator errors, P_12/P_13/GTU/Adnotacje fields, invoices for foreign buyers (EU, non-EU), foreign currency invoices, reverse charge, WDT, export, VAT exemption, advance invoices, corrective invoices, or any FA(3) logical structure question.

Generate corrective FA(3) invoices (faktury korygujące) for KSeF. Use this skill when the user has a faulty invoice and needs to produce a correction (KOR, KOR_ZAL, KOR_ROZ) or a "correction to zero" for wrong-buyer scenarios. The skill works as an interactive wizard: it accepts the original invoice (XML, pasted data, or description), identifies what needs correcting, asks targeted questions to fill any gaps, and produces a complete, validator-passing corrective invoice XML.