15 september 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 20 september 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 september 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 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) Terugkerend 20 oktober 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 oktober 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 15 november 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 20 november 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 november 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 15 december 2026 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 20 december 2026 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 december 2026 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 1 januari 2027 Poland JPK_CIT / JPK_KR_PD (structured accounting books) Poland: JPK_CIT digital accounting-books reporting becomes mandatory for remaining CIT taxpayers 12 januari 2027 Data Act Dataverordening (Data Act): cloudaanbieders moeten stoppen met kosten voor overstappen en data-egress 15 januari 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 20 januari 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 januari 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 15 februari 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 20 februari 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 februari 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 28 februari 2027 Poland KOBiZE national emissions database report Poland: annual report to the national GHG/emissions database (KOBiZE) due by end of February Terugkerend 15 maart 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 20 maart 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 maart 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 31 maart 2027 Poland CIT-8 annual return Poland: annual CIT-8 corporate income tax return due by 31 March Terugkerend 31 maart 2027 Poland environmental-use fee (opłata za korzystanie ze środowiska) Poland: annual environmental-use fee (opłata za korzystanie ze środowiska) due by 31 March Terugkerend 15 april 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 20 april 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 april 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 15 mei 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 20 mei 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 mei 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 15 juni 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 20 juni 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 juni 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 15 juli 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 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) Terugkerend 20 juli 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 juli 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend 15 augustus 2027 Poland ZUS social insurance contributions Poland: ZUS social insurance contributions and DRA declaration due by the 15th (legal persons) Terugkerend 20 augustus 2027 Poland CIT advance payments Poland: monthly CIT advance payment due by the 20th (quarterly option for small taxpayers) Terugkerend 25 augustus 2027 Poland JPK_V7 (VAT records and declaration) Poland: JPK_V7M monthly VAT return and payment due by the 25th Terugkerend