Electronic invoice in Poland
Comprehensive guide to mandatory B2B electronic invoicing in Poland – Legal framework, KSeF platform, obligations, and practical implementation
Poland is implementing a comprehensive national electronic invoicing system called KSeF (Krajowy System e-Faktur). Based on the 2021 Act on the National e-Invoicing System and EU derogation (Council Decision 2022/1003), KSeF will become mandatory for B2B transactions in 2026, creating a real-time transaction trail and transforming VAT reporting.
Key Milestones
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B2G Platform Launch
Public entities must accept structured electronic invoices via PEF (Platforma Elektronicznego Fakturowania).
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KSeF Voluntary Phase
Companies can voluntarily use KSeF for electronic invoicing, receiving benefits like accelerated VAT refunds.
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Universal B2B Mandate
ll VAT-registered taxpayers in Poland must use KSeF for B2B invoicing. Paper and PDF invoices no longer valid.
Poland is rolling out a national electronic invoicing system called KSeF (Krajowy System e-Faktur). It is based on the 2021 Act on the National e-Invoicing System and an EU derogation (Council Decision 2022/1003) allowing Poland to require electronic invoices for VAT purposes.
KSeF issues each invoice a unique ID and timestamp, validates its data and forwards it to the tax authority, creating a real-time transaction trail. This continuous transaction control (CTC) system effectively replaces parts of existing VAT reporting and provides a 10-year invoice archive.
B2G Requirements
B2B Mandate
B2C and Cross-Border Invoices
KSeF Format (FA_VAT/FA(3))
An XML structure defined by the Polish Ministry of Finance; mandatory for all invoices sent via KSeF.
PEF / Peppol BIS Billing 3.0
Based on EN 16931 and used for B2G invoices. Suppliers can issue invoices via PEF or KSeF, and PEF invoices will receive a KSeF number starting in 2026.
Interoperability and Connection
Poland’s e-invoicing strategy emphasizes interoperability. The Peppol BIS Billing 3.0 specification is the national CIUS (Core Invoice Usage Specification) and ensures compatibility with European standards.
KSeF is more than a transmission channel – it is a continuous transaction control (CTC) system. Each invoice is validated in real time, assigned a unique ID and timestamp, and transmitted to the tax authority, effectively replacing parts of the existing VAT reporting.
How We Support E-invoicing in Poland
As a Peppol Access Point and certified e-invoicing provider, we simplify compliance with the Polish mandate:
We convert your invoices into the required FA_VAT or Peppol BIS format and route them through KSeF or PEF as appropriate. Every invoice receives a KSeF number and meets EN 16931 standards.
We handle required authentication (qualified signature/seal) and submit invoices directly into KSeF, generating timestamps and unique IDs for legal validity.
Whether you’re a Polish business, EU supplier, or global company, our solution manages both incoming and outgoing invoices for B2G, B2B, and optional cross-border or B2C transactions.
We stay updated on KSeF developments (FA(3) schema, offline modes, tax-reporting changes) and adjust our service accordingly to ensure continued compliance and efficiency.
FAQ
Can I continue using PDF invoices after January 2026?
For B2B transactions with VAT-registered companies in Poland, no. From April 2026, only structured invoices sent via KSeF will be legally acceptable. However, PDF invoices remain valid for B2C transactions and invoices to foreign customers outside the mandate scope.
What if my counterparty is not ready to receive e-invoices through KSeF?
All VAT-registered companies in Poland must be capable of receiving invoices through KSeF by the mandatory deadline. If a recipient is not ready, they will be non-compliant with the obligation. We recommend early adoption and communication with your business partners to ensure a smooth transition.
Are small businesses also obligated?
Yes. From 1 April 2026, the obligation applies to all VAT-registered taxpayers in Poland conducting B2B transactions, regardless of company size or turnover. There is no exemption for small businesses.
Official Poland Resources
Summary
Poland has established a comprehensive legal framework for electronic invoicing. From 2026, KSeF will be mandatory for domestic business transactions, making Poland a pioneer in the EU’s mandatory B2B e-invoicing implementation.
The system is designed to streamline electronic invoices and take control of VAT reporting. By integrating KSeF with the Peppol network and using standard formats (FA_VAT and Peppol BIS Billing 3.0), Poland ensures both national compliance and international interoperability.
The trend clearly points toward standardization. As e-invoicing becomes mandatory both nationally and internationally, Polish companies that adopt Peppol-compatible formats and comply with archiving requirements will benefit from this transition, as they can use the same system and format to serve international partners.
Need Help with E-Invoicing Compliance?
As a certified Peppol Access Point, we provide complete e-invoicing solutions for businesses across Europe. Our platform handles format conversion, real-time validation, and seamless integration with national systems.
