Poland’s Krajowy System e-Faktur (KSeF) has operated since 2022, but its use was initially voluntary. The system is becoming mandatory in stages, marking a major change for businesses. Since February 1, 2026, the obligation has applied to the largest companies with annual sales above PLN 200 mln, while from April 1, 2026 it will cover almost all remaining VAT taxpayers.
KSeF is a central IT platform run by the Ministry of Finance of Poland for issuing, receiving and storing structured invoices. Under the new model, invoices are first sent to the state system, where they are formally verified and archived before being considered officially issued.
Experts say the change is not only technical but also organizational, especially for small and medium sized firms without extensive accounting or IT support. Structured invoices are stored in XML format and receive a unique identification number in the system. While the transition may initially raise concerns, proper implementation could streamline document management and improve cooperation with accounting services.