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KSeF number, QR code, and visualization — what's binding

A structured invoice in KSeF exists as an XML file in the FA(3) format. What you see on screen or on a printed PDF is a visualization of it — convenient to read, but not the document itself.

KSeF number

Section titled “KSeF number”

The KSeF number is assigned by the Ministry of Finance’s system at the moment the invoice is accepted — not before. It appears on the invoice card in Atestio, usually within a few seconds of submission. A document without a KSeF number hasn’t yet been accepted by the system.

QR code

Section titled “QR code”

Invoices generated by Atestio include a QR code on the printed PDF that leads to the payment link, if one was issued — see Payment link and split payment. Don’t confuse it with the verification elements that can appear on visualizations provided by the KSeF system itself — those are generated on the Ministry of Finance’s side and describe the official visualization of the document, not the PDF generated by Atestio.

Which document is binding

Section titled “Which document is binding”

The raw XML file registered in KSeF is the only legally binding document within the scope of the KSeF mandate. The PDF generated by Atestio exists only for readability — if a discrepancy ever arose between the content of the XML file and its PDF visualization, the XML file governs. The original XML file can be downloaded from the invoice card (Download XML (FA(3))).

Official Confirmation of Receipt (UPO)

Section titled “Official Confirmation of Receipt (UPO)”

Acceptance of the invoice by KSeF is confirmed by a UPO — see Invoice statuses and UPO.

What’s next

Section titled “What’s next”