The year 2026 is less about brand-new tax rules and more about a massive shift in how businesses report data to the government. The focus is on digital compliance – moving from paper and PDFs to real-time data sharing with tax authorities.
Mandatory e-invoicing (KSeF)
The National e-Invoicing System (KSeF) is finally becoming a reality after several delays. Invoices will no longer be just files sent between companies; they will be structured data records registered directly in the Ministry of Finance’s system.
International groups are particularly affected by the phased implementation of KSeF. Large entities (turnover over PLN 200m in 2024) face a February 1, 2026 deadline, with remaining VAT taxpayers joining on April 1. For the major taxpayers, full system integration will be needed to ensure compliance.
It is also important to note that KSeF generally also applies to international transactions where a Polish taxpayer issues an invoice to a foreign entity. While the foreign purchaser is not required to receive the invoice through KSeF and may get it outside the system, the obligation to issue the invoice within KSeF rests with the Polish taxpayer.
Mandatory application of KSeF will also affect foreign businesses operating in Poland through a fixed establishment.
Why it matters?
An invoice is officially “issued” only when it gets a KSeF number. This eliminates disputes over lost mail or delivery dates and gives the government a real-time view of all business transactions.
Digital corporate reporting (JPK_CIT)
At the same time, companies must start reporting their accounting books in a new digital format called JPK_CIT.
This will allow tax authorities to analyse company data much more deeply than before. The scope of reporting covers in particular: fixed assets, counterparty data, reconciliations between accounting and tax results and much more.
The largest taxpayers will submit their first digital reports in March 2026 (most probably the deadline will be extended to July 2026). Smaller businesses must ensure their systems are ready to report in 2027.
Global Minimum Tax (Pillar Two)
Although the global minimum tax rules have already entered into force, 2026 is the year in which they begin to have practical relevance. The first reporting obligations for the initial period will arise for Polish entities belonging to groups with consolidated revenues exceeding €750 million, alongside preparatory decisions that must be taken well in advance of any tax payments.
Particular attention is required where effective tax rates may be reduced by domestic incentives, such as R&D reliefs or special economic zones. While work is ongoing to adjust local incentive regimes to the pillar two framework, no binding solutions have been adopted as yet.
Temporary Bank Tax Increase
Banks and financial institutions face a specific change: a temporary increase in their corporate income tax (CIT) rate to 30% for the year 2026. This is intended to be a transitional measure before rates are gradually lowered in the following years.
Summary
Even though some planned reforms (like those for family foundations) were put on hold, 2026 will be an intense year from tax perspective. Since the legislative process is still active, new tax amendments could be introduced at any time. Businesses must follow these developments continuously, as tax changes in Poland are now often implemented on various dates throughout the year