🇵🇱 KSeF Invoice Viewer (Poland FA(3))
Read a faktura ustrukturyzowana without any software — since April 2026 every VAT-registered business in Poland invoices through KSeF, and what lands in your systems is FA(3) XML. This viewer turns it back into a readable invoice, entirely in your browser.
Parsed with your browser's XML engine — invoice data (parties, NIPs, amounts, bank account) never leaves your device.
How the ksef invoice viewer (poland fa(3)) works
A KSeF invoice is an XML document following Poland's FA logical structure — currently FA(3), mandatory since 1 February 2026 — with a <Faktura> root containing the header (Naglowek), the seller and buyer (Podmiot1/Podmiot2 with their NIP identifiers), and the invoice body (Fa) whose positional fields carry the data: P_1 issue date, P_2 invoice number, P_15 total due, FaWiersz line items, P_13/P_14 VAT sums per rate group. The viewer parses those fields and lays them out as the invoice a human expects — parties, dates, line table, VAT summary, payment account — and detects whether the file is FA(3) or the older FA(2). There's a print/save-as-PDF button for filing. Everything happens in your browser: a KSeF file names your counterparties, amounts and bank account, which is exactly the data not to upload to a random website.
The timeline that makes this an everyday need: large taxpayers have invoiced through KSeF since 1 February 2026, all VAT-registered businesses since 1 April 2026, and the smallest micro-entrepreneurs join by 1 January 2027 — after which penalties (up to 100% of the invoice's VAT) become enforceable. Receiving structured invoices has been mandatory for everyone since February 2026, so "a supplier sent me an XML" is now the normal case in Poland, not the exception. The XML in KSeF is the legally binding invoice; any PDF or paper copy is just a visualisation of it.
Frequently asked questions
What is KSeF and what is an FA(3) file?
KSeF (Krajowy System e-Faktur) is Poland's national e-invoicing clearance system: invoices are submitted to it as XML and legally exist once KSeF accepts them and assigns a KSeF number. FA(3) is the current XML structure those invoices follow — mandatory since 1 February 2026, replacing FA(2).
Who has to use KSeF, and from when?
Issuing became mandatory for large taxpayers (over PLN 200M turnover) on 1 February 2026 and for all other VAT-registered businesses on 1 April 2026; micro-entrepreneurs with small invoice volumes have until 1 January 2027. Receiving via KSeF has been mandatory for everyone since February 2026. 2026 is a grace period — from January 2027, penalties apply.
How do I open an FA(3) XML file I received?
Load it into this viewer — it parses the structure locally and displays the parties, dates, line items, VAT breakdown and payment details as a normal invoice, which you can print or save as PDF. No accounting software or KSeF login is needed to simply read the file.
Is the XML or the PDF the real invoice?
The XML. In the KSeF regime the structured file accepted by the system is the legally binding invoice; PDFs or printouts are visualisations. If they disagree, the XML governs — which is a good reason to check what it actually says.
Does this viewer work with FA(2) files too?
Yes — it auto-detects the variant from the header and reads both, flagging FA(2) files as the older structure. XRechnung, Factur-X and Peppol invoices use different standards; the general e-invoice viewer handles those.
Is my invoice uploaded to be read?
No — the XML is parsed by your browser's own engine and the page works offline. Counterparty names, NIPs, amounts and bank account numbers never leave your device.