Poland: annual CIT-8 corporate income tax return due by 31 March
Every year in March, due by the 31st. · For a standard 1 Jan-31 Dec financial year; companies with a non-calendar year file within 3 months of their own year-end. Retires one-off entry pl-cit8-financial-statements-krs-filing, which is now split into this CIT-8 entry and the separate pl-financial-statements-krs-yearly entry for the KRS/RDF filing.
What changes
Poland CIT taxpayers with a calendar financial year must file their annual CIT-8 corporate income tax return within 3 months of financial year-end - 31 March for a standard 1 January-31 December year - reconciling the year's CIT advances against the final liability.
Who is affected
All Poland-registered CIT taxpayers (sp. z o.o., S.A. and other CIT payers) with a calendar financial year.
Sizes: micro, small, medium, large · Sectors: All sectors
What to do
Close the books, compute the annual CIT liability against advances already paid, and file CIT-8 electronically by 31 March. Companies whose non-calendar financial year ends on a different date must file within 3 months of their own year-end instead.
Next occurrences
Penalty
Fines under the Fiscal Penal Code (Kodeks karny skarbowy) for late or missing CIT-8 filings, plus late-payment interest under the Tax Ordinance on any balance due.
Sources
- biznes.gov.pl - Zeznanie roczne osób prawnych CIT-8 (31 March deadline) (www.biznes.gov.pl)
Last verified 8 September 2026. Informational only, not legal advice.