How to register for KSeF? Access, sign-in, permissions
There is no password-based KSeF account. Learn how authentication works, who gets automatic permissions, and when you need the ZAW-FA form.
GuideJuly 22, 2026
Guide
KSeFGPT guide: practical articles on KSeF, FA(3), XML, deadlines, invoice errors and automation for companies and accounting teams.
Articles and instructions
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How to Check Whether KSeF Is Experiencing an Outage
KSeF is not responding, but is the system down or is the problem on your side? Check the live status, official Ministry announcements and invoice submission deadlines for each system state.
GuideJuly 19, 2026
How to Convert KSeF XML into a Readable PDF Invoice
Learn how to create a readable PDF from invoice XML, check the data and distinguish a preview from a KSeF-accepted invoice visualisation.
GuideJuly 10, 2026
How to Issue a Final Invoice After an Advance in KSeF
Learn when a final invoice is needed after an advance, how to deduct earlier payments and avoid settling the same sale twice.
GuideJuly 6, 2026
How to check invoice status in KSeF after submission?
You sent an invoice to KSeF, but you do not know whether it has been accepted, is still being processed, or was rejected? Check the status, reference number, KSeF number and UPO step by step.
GuideJuly 2, 2026
How to issue a VAT invoice in KSeF step by step
Follow the regular sales invoice process in KSeF: document type, invoice data, XML FA(3), validation, submission, KSeF number, and UPO.
GuideJuly 1, 2026
Invoice Types in KSeF: VAT, KOR, ZAL, ROZ and UPR
Learn how FA(3) identifies standard, corrective, advance, settlement and simplified invoices, and how to choose the right type before submitting it to KSeF.
GuideJune 30, 2026
KSeF and VAT Margin: How to Issue a Margin Invoice
How to record a VAT margin invoice in FA(3): Articles 119 and 120, P_PMarzy, P_13_11, MR_T, MR_UZ and pre-submission checks.
GuideJune 29, 2026
Advance Invoices in KSeF for Small Businesses
How to handle an advance payment in FA(3), when a settlement invoice is needed, and how to keep the KSeF number, UPO and corrections connected.
GuideJune 24, 2026
KSeF number on an invoice: where to find it and what to store
Learn what the KSeF number is, how it differs from the P_2 invoice number, where to find it and how to use it in UPO, JPK and payments.
GuideJune 24, 2026
KSeF for freelancers and sole proprietors: B2B invoices, costs and obligations
When to issue B2B invoices, how to receive costs, track UPO, KSeF number and accountant collaboration.
GuideJune 22, 2026
7 PDF-to-XML KSeF Conversion Errors
Learn the most common errors when converting a PDF invoice to FA(3) XML, their effects in KSeF and how to catch them before submission.
GuideJune 21, 2026