Poland: Tax Deadlines, Rates, and Limits for September 2026

Polish taxpayers and employers must navigate a series of deadlines and financial obligations throughout September 2026.

Individuals paying income tax via tax cards have until September 8 to submit their August 2026 declarations. Businesses involved in intra-community acquisitions of fuel must also submit their VAT-14 declarations by this date. For VAT-registered businesses, the deadline for submitting INTRASTAT declarations for August 2026 is September 10.

Mid-September brings further obligations. By September 15, legal entities and organizations without legal personality must pay property and forest taxes for September 2026, along with the third installment of agricultural tax. Businesses are also due to pay the second installment of their transport vehicle tax by this date.

Towards the end of the month, those paying flat-rate income tax for August 2026 must do so by September 21. This date also applies to dominant companies within a capital group paying advance tax for August, as well as employers and contractors paying advance income tax on employee wages and other employment-related payments for the same period.

September 25 is the deadline for VAT payers to submit their August 2026 VAT returns and summary information on VAT UE for intra-community transactions. This date also applies to VAT payers submitting JPK_V7M files for August and JPK_V7K (registration part) for September. Those liable for excise tax must settle their August 2026 excise tax and submit declarations. Additionally, businesses must settle sugar tax and retail sales tax for August 2026.

Finally, September 30 is the deadline for employers obligated to maintain a company social benefits fund to transfer the remaining basic contributions. This date also marks the deadline for employers to grant overdue annual leave, specifically leave from 2025 and previous years. Notably, overdue annual leave from 2022 will become statute-barred on October 1, 2026.