Poland — Peppol & e-invoicing mandate updates (peppolo.com) https://www.peppolo.com/countries/poland/ Mandate changes, deadlines and Peppol news for Poland, by Verteco. Poland confirms KSeF mandatory e-invoicing schedule https://www.peppolo.com/resources/news/poland-ksef-schedule-confirmed/ https://www.peppolo.com/resources/news/poland-ksef-schedule-confirmed/ Thu, 20 Aug 2026 00:00:00 GMT KSeF becomes mandatory for large taxpayers on 1 February 2026 and for all other businesses on 1 April 2026.