Integrations

KSeF

Polish national e-invoicing system

KSeF is Poland's national e-invoicing system. An online store passes order data to its invoicing software and receives the invoice's KSeF number back.

Official site

What is KSeF?

KSeF (Krajowy System e-Faktur) is Poland's National e-Invoicing System, run by the Ministry of Finance, through which structured invoices in XML format are issued and received. Each invoice is given a unique KSeF number, and the original is the document held in the system – a PDF with a QR code is only a visualisation. Mandatory KSeF invoicing covers invoices issued to businesses and is being phased in across 2026 and 2027.

How we use it at Koda Plus

We prepare online stores and wholesale platforms for KSeF as part of our order and invoice automation service. We design a chain in which the store collects and validates invoice data, the order reaches the invoicing system, such as Subiekt GT or Comarch Optima, and the KSeF number comes back to the order and the customer's account. We also plan for corrections, offline mode and separate B2B and B2C flows.

When it makes sense

  • Your store or wholesale business invoices other companies
  • Invoices are currently created by hand from exported orders
  • B2B customers should see the KSeF number next to each order in their account
  • You serve businesses and consumers at the same time

Frequently asked questions
KSeF

  • Does an online store have to connect to KSeF directly?

    No. The invoice is sent to KSeF by the system that issues it, usually accounting software or an ERP. The store passes that system complete, correct order data and receives the KSeF number back.

  • When does KSeF become mandatory?

    Under the schedule as of July 2026, the largest taxpayers must issue invoices in KSeF from 1 February 2026, other businesses from 1 April 2026 and the smallest from 1 January 2027. Receiving invoices through KSeF has been mandatory for everyone since 1 February 2026, so confirm the date that applies to your company with your accountant.

  • Do consumer invoices have to go through KSeF?

    Not necessarily – under current rules the obligation covers invoices issued to businesses, while consumer invoices may be issued in KSeF voluntarily. Fiscal receipts work independently of KSeF, so a store serving both segments has to route each document correctly.

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