From 1 February 2026, Poland will introduce mandatory e-invoicing for B2B and B2G transactions via the KSeF (National E-Invoicing System). While implementation was initially planned for 2024, it was postponed both to give businesses more time to adapt and to allow the government to strengthen the technical infrastructure, which was not sufficiently efficient. Companies must prepare for structured e-invoices, VAT compliance through KSeF, and new rules for correcting documents. This guide explains the e-invoicing requirements in Poland, the role of the Polish Ministry of Finance, and the benefits and challenges of the new system.
Poland’s Invoicing and Tax Regulations: 2024–2025 Update
Poland’s invoicing system has undergone major reforms since the introduction of the Krajowy System e-Faktur (KSeF) in 2022. Initially optional, e-invoicing in Poland was expected to become mandatory in July 2024, but the Ministry of Finance postponed the mandate. The delay reflects both the need for businesses to adapt and the need for the state to build more efficient IT infrastructure (KSeF 2.0).
For businesses, the transition period (2024–2025) remains crucial. Invoices must comply with the Polish VAT Act, and companies can voluntarily issue e-invoices via the KSeF platform. However, the mandatory timeline is phased:
- 1 February 2026 – Large taxpayers established in Poland must issue invoices via KSeF for B2B transactions.
- 1 April 2026 – Medium and small taxpayers follow.
- 1 January 2027 – All taxpayers, including foreign businesses with a fixed establishment in Poland, become subject to the obligation, except digitally excluded taxpayers with turnover below PLN 10,000 per month.
It is worth mentioning that regardless of when a taxpayer is obliged to start issuing sales invoices via KSeF, they may be required to use KSeF earlier in order to retrieve purchase invoices issued by companies already subject to the obligation at an earlier stage.
Key Deadlines
- 1 February 2026 – Large taxpayers (B2B)
- 1 April 2026 – Medium and small taxpayers (B2B)
- 1 January 2027 – Taxpayers with turnover below PLN 10,000 per month
VAT Invoice Requirements and Compliance in Poland
Core requirements under the Polish VAT Act
- Invoices must contain structured data (XML format) aligned with the Ministry of Finance schema.
- The KSeF number (KSeF ID) is assigned upon successful submission.
- As a rule, invoices must be issued no later than the 15th day of the month following the month in which the supply of goods or services took place, unless specific provisions provide otherwise.
- Corrections must be made via KSeF, ensuring audit traceability.
- The original invoice is the version stored in KSeF; companies cannot alter it outside the platform.
VAT compliance and tax reporting
- Tax authorities will be able to very easily verify the data declared in VAT returns against invoices stored in KSeF, enabling faster and more accurate tax control.
- Thanks to the new system, tax authorities will also be able to detect tax fraud more easily and initiate audits more quickly in relation to suspicious transactions, while automatic reporting reduces discrepancies and improves tax compliance.
- The Ministry of Finance expects that the system will cut VAT fraud and recover an estimated PLN 200 million annually.
E-Invoicing in Poland: Key Features of KSeF
National Electronic Invoicing System (KSeF)
- A centralized platform managed by the Polish Ministry of Finance.
- Supports structured invoices compliant with Peppol BIS Billing 3.0 standards.
- Designed for B2B, B2G, and cross-border transactions.
KSeF 2.0 and the 2025–2026 implementation
- The upgrade aims to handle higher volumes as mandatory e-invoicing becomes reality.
- Integration with ERP and accounting systems is a must.
- A focus on both domestic and EU-wide compliance (e.g., e-invoicing via Peppol).
Correcting Documents in Poland: E-Invoicing Rules
- Corrections to invoices must be submitted via KSeF.
- Starting from the entry into force of KSeF, minor corrections to invoices will no longer be possible using a corrective note; this document will disappear from circulation.
- The corrected e-invoice will receive a new KSeF number, but both original and corrected versions remain in the system.
- Businesses must ensure compliance with VAT rules when issuing corrections.
Benefits of Mandatory E-Invoicing in Poland
- Improved compliance with Polish VAT regulations.
- Faster invoice exchange and reduced administrative burden.
- Tax authorities gain real-time visibility of transactions.
- The KSeF system helps prevent tax evasion and fraud, thereby improving the overall competitiveness of businesses.
Timeline of Poland’s E-Invoicing Mandate
- 1 January 2022 – KSeF introduced (voluntary phase).
- 1 July 2024 – Planned start of mandatory e-invoicing (postponed).
- 1 February 2026 – Mandatory for large taxpayers.
- 1 April 2026 – Mandatory for medium and small taxpayers.
- 1 January 2027 – Mandatory for digitally excluded taxpayers under the threshold.
Conclusion: Preparing for the 2026–2027 Mandates
Businesses operating in Poland must adapt their invoicing and tax compliance processes now. Although mandatory e-invoicing via KSeF begins in stages from 1 February 2026, early adoption will help companies integrate seamlessly with the KSeF platform, ensure VAT compliance, and benefit from streamlined reporting. Companies should review their ERP systems, train accounting staff, and establish compliance workflows with KSeF ahead of the deadlines.
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