Poland is moving closer to the full rollout of its national e-invoicing system, KSeF, which will become mandatory in phases starting in 2026. The first stage will take effect in February 2026, introducing obligations for large taxpayers, followed by the second stage in April 2026, when the scope will extend to all other taxable persons. These deadlines mark a major shift toward real-time structured invoicing across the Polish economy.
Currently, the KSeF test environment is unavailable, having been temporarily closed on the 1st of September. Authorities have confirmed that it is scheduled to reopen at the end of September, giving companies renewed access to test their systems and prepare for the upcoming mandate. Businesses are strongly encouraged to use this window to finalize integration and ensure compliance ahead of the phased introduction.
With the deadlines approaching, taxpayers operating in Poland should begin reviewing their readiness plans. The reopening of the test system will be a critical opportunity to validate technical connections and internal processes, as the February and April 2026 milestones will leave little room for last-minute adjustments.
