15. September 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. September 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. September 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 1. Oktober 2026 Poland e-Doręczenia (Ustawa o doręczeniach elektronicznych) Poland: e-Doręczenia address becomes mandatory for CEIDG businesses registered before 2025 15. Oktober 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. Oktober 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. Oktober 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 15. November 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. November 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. November 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 15. Dezember 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. Dezember 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. Dezember 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 1. Januar 2027 Poland JPK_CIT / JPK_KR_PD (structured accounting books) Poland: JPK_CIT digital accounting-books reporting becomes mandatory for remaining CIT taxpayers 12. Januar 2027 Data Act Data Act: Cloud-Anbieter dürfen keine Wechsel- und Datenausgangsgebühren mehr verlangen 15. Januar 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. Januar 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. Januar 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 15. Februar 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. Februar 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. Februar 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 28. Februar 2027 Poland KOBiZE national emissions database report Poland: annual report to the national GHG/emissions database (KOBiZE) due by end of February Wiederkehrend 15. März 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. März 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. März 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 31. März 2027 Poland CIT-8 annual return Poland: annual CIT-8 corporate income tax return due by 31 March Wiederkehrend 31. März 2027 Poland environmental-use fee (opłata za korzystanie ze środowiska) Poland: annual environmental-use fee (opłata za korzystanie ze środowiska) due by 31 March Wiederkehrend 15. April 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. April 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. April 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 15. Mai 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. Mai 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. Mai 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 15. Juni 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. Juni 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. Juni 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 15. Juli 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 15. Juli 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) Wiederkehrend 20. Juli 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. Juli 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend 15. August 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Wiederkehrend 20. August 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Wiederkehrend 25. August 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Wiederkehrend