Poland’s Ministry of Finance has extended the phased launch of the KSeF e‑invoicing system, with large taxpayers required to go live on 1 Feb 2026 and other businesses on 1 Apr 2026. No monetary penalties will apply for KSeF breaches during 2026, but administrative fines may be imposed from 1 Jan 2027. Additional requirements include bank‑transfer ID references from 1 Aug 2026 and mandatory acceptance of KSeF invoices by Polish VAT‑registered customers.