Guide to Poland E-Invoicing: Mandatory Updates and Key Deadlines for 2026
The Krajowy System e-Faktur (KSeF) will become mandatory in 2026 requiring businesses in Poland to switch to structured e-invoicing for compliance and efficiency. The Ministry of Finance has introduced key updates, including the FA_VAT (3) schema, new regulations, and a phased rollout timeline.
In this Guide to Poland E-Invoicing, we will cover KSeF Poland E-Invoicing deadlines, technical updates, and how to prepare for the transition.
What is Poland E-Invoicing?
E-invoicing is the process of issuing, receiving, and processing invoices in a structured digital format. Unlike traditional paper invoices or scanned PDFs, e-invoices are created, transmitted, and processed electronically in a standardized format.
In Poland, KSeF (Krajowy System e-Faktur) is the national e-invoicing system designed to streamline invoicing, improve tax compliance, and reduce fraud.
New KSeF Implementation Timeline (2025-2026)
The Ministry of Finance has provided a detailed timeline for the transition to mandatory KSeF:
• January 2025 – Launch of the KSeF hotline to support taxpayers
• Q1 2025 – Finalization of legislation related to KSeF
• June 2025 – Publication of API documentation for integration with KSeF
• June–August 2025 – API testing phase
• September–December 2025 – Open testing of KSeF for taxpayers
• November 2025 – Alignment of KSeF environments (TEST, DEMO, PROD) and creation of PROD environment 2.0
• February–April 2026 – Mandatory e-invoicing rollout in phases
Mandatory E-Invoicing Deadlines
The final dates for mandatory e-invoicing via KSeF have been confirmed:
• 1 February 2026 – Mandatory e-invoicing for taxpayers whose sales (including VAT) exceeded PLN 200 million (approx. EUR 46 million) in 2025
• 1 April 2026 – Mandatory e-invoicing for all other taxpayers
Key Business & Legal Changes in the KSeF Draft Act
The draft Act includes several important legal and business-related updates:
1. Voluntary B2C E-Invoicing
While B2B e-invoicing will be mandatory, businesses will have the option to issue B2C e-invoices voluntarily via KSeF.
2. Invoices via Cash Registers Allowed Until 1 August 2026
Taxpayers can continue issuing invoices via cash registers until 1 August 2026 before fully integrating with KSeF.
3. Mandatory KSeF Number on Bank Transfers (from 1 August 2026)
The KSeF identification number must be included in bank transfers when making payments for invoices. This also applies to the split payment mechanism (MPP).
4. Offline Invoicing Mode Allowed Until End of 2026
Businesses will be able to issue invoices outside KSeF and send them to the system within 1 business day. This offline mode is voluntary and aims to ensure business continuity in case of system failures.
5. Transition Period for Micro-Enterprises (Until September 2026)
Taxpayers meeting both of the following conditions will not be required to issue e-invoices until September 2026:
• Individual invoices up to PLN 450 (approx. EUR 100)
• Monthly total sales value up to PLN 10,000 (approx. EUR 2,300)
This provides small businesses additional time to transition to structured e-invoicing.
Technical Updates in Schema FA_VAT (3)
Alongside legal changes, the Polish Ministry of Finance has introduced significant technical updates in the new FA_VAT (3) schema, enhancing functionality and compliance for businesses using KSeF.
1. E-Invoice Attachments
Businesses can now attach documents directly to e-invoices in KSeF. The FA_VAT (3) schema includes an “Attachment” node, which allows structured data and customizable fields to accommodate various industry-specific invoicing needs.
2. QR Code Certificates (Available from 1 November 2024)
Taxpayers will be able to generate and download invoice issuer certificates using QR codes. These QR code-based certificates will serve as a backup in case of system failures or when using offline invoicing, ensuring business continuity.
3. Alignment of KSeF Environments (Q4 2025)
The current optional KSeF system will be replaced with the mandatory KSeF system. Taxpayers will gain access to the new functionalities and technical solutions before the final transition to mandatory e-invoicing on 1 February 2026.
4. New Rules for Payment Deadlines
The FA_VAT (3) schema introduces updated rules for payment deadlines, enhancing clarity and consistency in invoice processing. These updates aim to align payment schedules with the new structured invoicing framework.
5. JST Label for Local Government Units
A new JST label has been added to ensure local government units have proper access to invoices related to their financial operations. This enhancement supports public sector compliance with structured invoicing requirements.
6. Employee Role Added Under Podmiot3 Node
The FA_VAT (3) schema introduces a new “employee” role under the Podmiot3 node, allowing for better structuring of e-invoice authorization. This addition provides organizations with greater control over invoice management by specifying employee-level authorization rights.
How You Should Prepare for KSeF
To ensure a smooth transition to KSeF, you should take the following key steps:
1. Ensure Your Compliance with KSeF Deadlines
Determine whether your business falls under the February 2026 deadline (for large taxpayers) or the April 2026 deadline (for all other taxpayers). If you qualify for the transition period for micro-enterprises, take advantage of the extended timeline to prepare.
2. Adapt Your Invoicing System to FA_VAT (3)
Update your invoicing system to support attachments, QR code certificates, and new payment rules. Make sure you include the KSeF identification number in bank transfers by August 2026 to comply with new payment regulations.
3. Test Your API Integrations and Offline Mode
Participate in API testing (June–August 2025) and open KSeF tests (September–December 2025) to verify your system’s integration before full implementation. If you plan to use offline mode, set up a process to submit invoices to KSeF within one business day to stay compliant.
4. Train Your Internal Teams
Ensure your finance and accounting teams are trained on the new KSeF requirements, including attachment management, QR codes, and invoice submission.
How Flick Network Can Help You with KSeF Compliance
• Seamless KSeF Integration – Flick Network’s system is fully compatible with KSeF and ensures quick and easy e-invoicing.
• Automated Compliance – Our platform automatically adapts to the latest FA_VAT (3) schema updates, including attachments, QR codes, and structured data support.
• Real-Time API Connectivity – Keep your invoicing process efficient with real-time API integrations that ensure smooth invoice submission and retrieval.
• Offline Mode Support – Easily issue invoices outside KSeF and submit them within the required timeframe.
• User-Friendly Dashboard – Monitor your invoices, payments, and KSeF compliance in one place.
Flick Network offers a complete e-invoicing solution in Poland that ensures seamless KSeF compliance. Our platform supports automated updates real-time API connectivity and offline invoicing for smooth operations. With a user-friendly dashboard businesses can easily manage invoices payments and compliance. Contact Flick Network for any queries and support in e-invoicing in Poland.
Conclusion
With mandatory Poland E-Invoicing deadlines approaching on 1 February 2026 for large taxpayers and 1 April 2026 for all others, now is the time to act. Flick Network offers a seamless KSeF-compliant solution with real-time API connectivity, offline mode support and an easy-to-use dashboard. We hope you got to know all the info you need on the Poland e-invoicing mandate from this Guide to Poland E-Invoicing blog. Contact us to learn more about e-invoicing in Poland.