Poland introduces KSeF: why e-invoicing becomes mandatory and what it means
Updated: January 2026.
Poland is moving to make structured e-invoices the norm through KSeF (Krajowy System e-Faktur), a national system where invoices are created, transmitted, received, and stored in a shared digital flow. The rationale is both fiscal-policy driven and practical: stronger tools to counter VAT fraud, more standardised business processes, and a more data-driven tax administration.
What is KSeF in practice?
KSeF is a state-run, centralised platform for so-called faktury ustrukturyzowane, i.e., structured e-invoices in a standardised format. The system covers the full lifecycle from issuance to access and storage, and each invoice receives a unique identification number in KSeF. This means invoice information is increasingly treated as machine-readable data that can be integrated into ERP/accounting systems, bookkeeping, and compliance controls.
When does KSeF become mandatory?
Polish authorities have communicated a phased rollout. From 1 February 2026, the obligation applies to large taxpayers whose 2024 sales exceeded PLN 200 million (including VAT). From 1 April 2026, the requirement is extended to other businesses subject to invoicing obligations, with specific relief or deferrals for the smallest taxpayers in certain cases.
Why is Poland introducing KSeF? Five drivers behind the reform
1. Tax policy and enforcement: more effective VAT controls
The core idea is that structured B2B invoices pass through a shared system, giving the tax authority faster and more standardised access to invoice data. The EU decision granting Poland a special derogation to introduce mandatory e-invoicing highlights this rationale: the measure is intended to strengthen analytical capability, enable more automated consistency checks (for example, between declared and paid VAT), and improve verification of VAT refund claims.
2. The EU framework: Poland needed a derogation while the EU is digitising VAT flows
To mandate e-invoicing within the EU VAT framework, Poland required a derogation. This was granted through Council Implementing Decision (EU) 2022/1003, allowing Poland to depart from certain VAT Directive rules in the scope covered by the decision.
In parallel, the EU is pursuing a broader reform agenda through VAT in the Digital Age (ViDA). The package was adopted in March 2025 and will be implemented in stages, including digital reporting requirements for cross-border B2B transactions from 1 July 2030 and continued harmonisation of national solutions through 2035.
3. Digitisation and efficiency: from documents to data
KSeF is not only about control. Through a standard format and central distribution, the invoice shifts from being a “document” (paper/PDF) to structured data that can be automated across business workflows, reducing manual work and friction in invoicing and bookkeeping. This is also a recurring point in official materials: standardisation, faster circulation, and less uncertainty about delivery and access to invoices.
4. Business benefits: practical simplifications that support the transition
Official Polish sources point to several practical benefits. Examples include a shorter standard timeline for VAT refunds when e-invoices are used in KSeF (40 days instead of 60), reduced need for in-house archiving through longer access/storage, lower error risk via a standardised format, faster document circulation, and easier import of invoice data into accounting/ERP systems.
5. Policy and administrative direction: a broader digital transformation of KAS
KSeF fits into a wider digital transformation programme for Poland’s tax administration, Krajowa Administracja Skarbowa (KAS). Official government communications describe that KAS publishes planned e-services and changes on a rolling basis within a multi-year plan for 2024–2028, enabling businesses to prepare in good time.
Closing note
In practice, KSeF is more than a new invoice format. It represents a shift toward standardised, data-driven processes where the invoice becomes integrated into reporting and controls. And as the EU moves toward more digital VAT reporting through ViDA, KSeF is a clear example of the direction of travel: more structure, more automation, and more near-real-time oversight.