KSeF (Krajowy System e-Faktur) is the national eInvoicing system in Poland. The Payhawk integration automates the retrieval and processing of these structured eInvoices, ensuring tax compliance and reducing manual data entry.
The KSeF number
The KSeF number is assigned by the government platform once an eInvoice is cleared. This number is not contained within the FA_VAT eInvoice XML itself. Payhawk stores the KSeF number as a saved reference for the expense, displaying it in the platform and on the generated visualization PDF. The KSeF number is also transferred to the ERP as part of the document name.
XML eInvoices and visualization PDFs
The FA_VAT XML file is the legal eInvoice. The PDF is a generated visualization intended for human review and is not the source of truth for accounting. Payhawk preserves the original XML and generates the PDF preview directly from that data.
KSeF eInvoicing data retrieval
KSeF delivery is mandatory for all eInvoices associated with a registered entity. The feed cannot be filtered by payment method, supplier, or payment status.
If accounts payable are maintained in an ERP while cards are managed in Payhawk, the same eInvoice will appear in both systems. Migrating all accounts payable into Payhawk eliminates this duplication.
Assignment of KSeF eInvoices
eInvoices delivered via KSeF follow the standard eInvoicing assignment workflow:
Buyer contact matching - Payhawk scans the XML for buyer contact information. If an email address or name matches a Payhawk user, that user is assigned as the expense owner.
Purchase order matching - If the eInvoice is automatically matched to a purchase order, the owner of that purchase order is assigned as the bill owner.
Exporting the KSeF number to your ERP
When Payhawk exports a KSeF eInvoice, it sets the KSeF number as the name of the exported document. From there, you can add a script in your ERP that copies the document name into a custom field of your own, such as a field holding the KSeF invoice ID.
For MS Business Central and Oracle NetSuite, the exported attachment file name is the KSeF ID on its own, followed by the original file extension. This applies automatically to eInvoices received through KSeF, with no setup on your side:
Only files that came in through KSeF are named this way. Documents that carry an external identifier from another source, such as Peppol or the French PPF, keep the standard descriptive file name.
Files exported before this naming was introduced keep the names they already have. Payhawk does not rename them.
In Oracle NetSuite, when two files in the same export share a KSeF ID, for example a document and its generated preview, one file keeps the plain KSeF ID as its name and each other file gains a short suffix, so every file stays recoverable.
To go back to the full descriptive file name instead, contact Payhawk support. The setting is stored per integration connection, so it applies to one ERP connection at a time.
Current limitations
The following features are not currently supported for KSeF eInvoices:
Split-payment (mechanizm podzielonej płatności) handling.
NBP FX-rate application.