On 27 August 2025, Polish President Karol Nawrocki signed into law the Act of 5 August 2025 amending the Value Added Tax Act and certain other Acts in relation to the mandatory use of the National e-Invoicing System (Krajowy System e-Faktur - KSeF). The Act was published in the Official Gazette on 1 September 2025. As previously reported, the KSeF was to be mandatory from 1 July 2024, but this…