15 September 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 September 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 September 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 1 October 2026 Poland e-Doręczenia (Ustawa o doręczeniach elektronicznych) Poland: e-Doręczenia address becomes mandatory for CEIDG businesses registered before 2025 15 October 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 October 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 October 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 15 November 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 November 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 November 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 15 December 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 December 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 December 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 1 January 2027 Poland JPK_CIT / JPK_KR_PD (structured accounting books) Poland: JPK_CIT digital accounting-books reporting becomes mandatory for remaining CIT taxpayers 12 January 2027 Data Act Data Act: cloud providers must stop charging switching and data-egress fees 15 January 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 January 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 January 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 15 February 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 February 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 February 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 28 February 2027 Poland KOBiZE national emissions database report Poland: annual report to the national GHG/emissions database (KOBiZE) due by end of February Recurring 15 March 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 March 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 March 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 31 March 2027 Poland CIT-8 annual return Poland: annual CIT-8 corporate income tax return due by 31 March Recurring 31 March 2027 Poland environmental-use fee (opłata za korzystanie ze środowiska) Poland: annual environmental-use fee (opłata za korzystanie ze środowiska) due by 31 March Recurring 15 April 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 April 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 April 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 15 May 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 May 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 May 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 15 June 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 June 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 June 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 15 July 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 15 July 2027 Poland annual financial statements - KRS/RDF filing Poland: e-financial statements filing to KRS via RDF due within 15 days of approval (by 15 July for calendar-year filers) Recurring 20 July 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 July 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring 15 August 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Recurring 20 August 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Recurring 25 August 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Recurring