Poland: Mandatory B2B Electronic Invoicing as of February 2026

B2B electronic invoicing in Poland

Poland has entered a new phase in its B2B e-invoicing mandate. Since February 1, 2026, the country has been gradually rolling out mandatory e-invoicing through KSeF (Krajowy System e-Faktur), Poland’s National E-Invoicing System.

The new requirements are transforming the way businesses issue, receive, and process invoices in Poland. Rather than exchanging traditional invoices directly between suppliers and customers, businesses covered by the mandate must issue structured electronic invoices and process them through the KSeF platform.

For businesses operating in Poland, particularly multinational companies that manage invoicing through centralized ERP systems, complying with KSeF involves far more than adopting a new invoice format.

Companies must consider ERP integration, data quality, connectivity with KSeF, authentication, response handling, and contingency procedures to ensure their invoicing processes continue to run smoothly.

In this guide, we explain how KSeF works in 2026, which businesses are affected, and the steps companies need to take to comply with Poland’s e-invoicing requirements.

Phased Rollout (KSeF 2.0)

KSeF is being introduced in stages, with different requirements taking effect over time. These are the key dates businesses need to be aware of:
 

What is Poland's National E-Invoicing System (KSeF)?

KSeF (Krajowy System e-Faktur) is Poland’s National E-Invoicing System, a centralized government platform operated by the Polish tax administration for issuing, receiving, and accessing structured electronic invoices.

Under the KSeF e-invoicing model, businesses generate invoices in the required structured format and submit them electronically to the national platform. KSeF validates each invoice and, once it has been successfully processed, assigns it a unique KSeF identification number.

Unlike systems designed primarily for post-issuance tax reporting, KSeF is an integral part of the invoice exchange process itself. Businesses subject to Poland’s e-invoicing requirements must therefore incorporate KSeF into their invoicing workflows rather than simply report invoice data after an invoice has been issued.

KSeF also provides centralized access to invoice data and stores electronic invoices for 10 years.
For businesses, this has significant operational implications. Their invoicing processes must be able to communicate reliably with the KSeF platform while keeping ERP, accounting, and financial systems synchronized. This requires companies to consider not only invoice generation, but also system integration, data consistency, document status management, and the reliable exchange of information between KSeF and their internal systems.

How Will KSeF Affect B2B Payments from 2027?

From January 1, 2027, B2B payments between active VAT taxpayers in Poland will be required to include the relevant KSeF reference. This introduces an additional compliance requirement for businesses using Poland’s National E-Invoicing System (KSeF).

Although the KSeF mandate began taking effect in February 2026, businesses should also prepare for this next major change to their payment processes. From 2027, KSeF references will need to be included when making B2B payments covered by the requirement.

The reference required will depend on whether the payment covers one or multiple invoices:
Payment for a single invoice: The payment must include the KSeF number assigned to that specific invoice.

Payment covering multiple invoices: The payment must include a collective identifier generated through KSeF.

What Is the KSeF Collective Identifier?

The KSeF collective identifier is a reference that, from January 1, 2027, will allow businesses in Poland to link a single B2B payment to a group of at least two structured invoices issued by the same seller.

KSeF will also allow users to decode a collective identifier to determine which invoices it covers. Businesses will be able to check the invoices included in a specific identifier and identify the collective identifiers in which a particular invoice appears.

This functionality will be particularly important for companies that make consolidated or bulk payments covering multiple invoices from the same supplier. Businesses should therefore ensure that their ERP, accounting, treasury, and payment processes are ready to generate, store, and manage KSeF collective identifiers as part of their B2B payment workflows from 2027.

How Does the KSeF E-Invoicing Process Work?

The KSeF e-invoicing process can be integrated directly into a company’s existing ERP, accounting, and invoicing workflows. In an automated environment, invoice data is generated internally, converted into the structured XML format required by KSeF, and submitted electronically to Poland’s National E-Invoicing System.

A typical KSeF e-invoicing workflow involves the following steps:

1. Invoice data is generated: The company’s ERP, accounting, or invoicing system creates the invoice data.
2. The invoice is converted to the required KSeF format: The data is transformed into the structured XML format required by KSeF.
3. The invoice is submitted to KSeF: The structured electronic invoice is transmitted to the KSeF platform for processing.
4. KSeF processes the invoice: The platform processes the document and returns information about its status.
5. A unique KSeF number is assigned: Once the invoice has been successfully accepted, it receives its unique KSeF identification number.
6. The response is synchronized with internal systems: KSeF status information and identifiers can be fed back into the company’s ERP and other financial systems, giving finance teams visibility throughout the invoice lifecycle.

For companies processing high volumes of invoices, automating the KSeF workflow can significantly reduce manual intervention and help keep ERP and accounting data synchronized with the KSeF platform. This is particularly important for maintaining efficient, scalable e-invoicing processes while meeting Poland’s KSeF compliance requirements.

What E-Invoice Format Does KSeF Require?

KSeF requires structured electronic invoices in XML format. Under Poland’s 2026 e-invoicing mandate, invoices submitted through the KSeF platform must follow the required logical structure so they can be correctly validated and processed by the system.

A key change introduced with the 2026 KSeF requirements is the FA(3) logical structure, which replaces the previous FA(2) schema.

FA(3) defines the structure, data fields, and information required to generate a KSeF-compliant electronic invoice. Businesses must therefore ensure that their ERP, accounting, or invoicing systems can generate invoice data according to the FA(3) structure before submitting it to KSeF.

The FA(3) structure:

• Introduces new mandatory and optional fields.
• Strengthens validation controls.
• Improves the consistency of tac and accounting data.
• Incorporates adjustments derived from public consultation and experience during the voluntary period.

What is the KSeF certificate used for?

The KSeF certificate is one of the methods available for authenticating yourself in the system.

In addition, it is mandatory to mark an invoice with a QR code that allows the issuer's identity to be verified when invoices are issued in special modes: offline24, offline (due to system unavailability), and emergency mode.

Types of KSeF certificates

In the KSeF (Krajowy System e-Faktur) system, there are two types of certificates, each with a different purpose:

1. KSeF certificate for authentication
   • This is mandatory for issuing invoices in special modes: offline24, offline due to system unavailability, and emergency mode.
   • It allows the user to access and operate in the system on behalf of the taxpayer (according to the permissions granted).
   • It works as an alternative to other authentication methods, such as qualified electronic signature, qualified electronic seal, or trusted profile.
2. KSeF certificate for special modes (offline)
   • This is mandatory for issuing invoices in special modes: offline24, offline due to system unavailability, and emergency mode.
   • It allows a verification code (QR) to be included on the invoice to confirm the identity of the issuer when the invoice is issued outside the system and subsequently sent to KSeF.

New features in the national electronic invoicing system (KSeF)

1. Offline mode until the end of 2026

Voluntary use of offline mode is permitted until December 31, 2026. This mechanism allows invoices to be issued outside the system in specific situations, with subsequent submission to the KSeF.

The concept of “offline24” is also introduced, which allows the invoice to be sent the next day in certain technical cases.

2. B2C invoicing

Invoices to end consumers (B2C) may be issued through KSeF on an optional basis.

3. Invoice attachments

Attachments may be added to structured invoices, regardless of the sector of activity.

4. Low-value invoices

Taxpayers who issue simplified invoices for low amounts (up to PLN 450 per invoice or PLN 10,000 per month) may continue to use the current format until September 30, 2026.

5. KSeF number in payments

The obligation to include the KSeF number in bank transfers (including payments with a split payment mechanism) will apply to payments made from August 1, 2026. Until that date, no penalties will be imposed in relation to this obligation.

How Should Businesses Prepare for KSeF Compliance?

To prepare for KSeF compliance in Poland, businesses should first identify which legal entities and invoicing flows fall within the scope of the mandate. They should then assess the entire invoice lifecycle, from invoice creation and data validation to KSeF submission, status management, and synchronization with internal systems.

A successful KSeF implementation requires more than generating invoices in the correct format. Businesses need to understand where invoice data originates, how it is validated, which ERP and accounting systems are involved, how invoices are transmitted to KSeF, and how responses from the platform are returned to their internal systems.

Key areas businesses should address when preparing for KSeF include:

• FA(3) data mapping and validation: Ensure invoice data can be mapped to the required FA(3) logical structure and validated before submission.
• ERP and accounting system integration: Connect existing business systems with KSeF to automate invoice submission and receipt.
• KSeF authentication and permissions: Define how users and systems will authenticate with KSeF and manage the appropriate access rights.
• KSeF certificates and QR code requirements: Prepare for the technical requirements associated with KSeF certificates and the use of QR codes where applicable.
• Incoming invoice processing: Establish automated processes for receiving and integrating supplier invoices from KSeF.
• Status and response management: Ensure KSeF responses, identifiers, and invoice statuses are captured and synchronized with internal systems.
• Offline and contingency procedures: Define how invoices will be handled when KSeF or the company’s connection to the platform is temporarily unavailable.
• Invoice storage and traceability: Maintain reliable access to invoice information and a clear audit trail throughout the invoice lifecycle.

For multinational companies, scalability should also be a key consideration. An organization implementing KSeF in Poland may simultaneously be adapting to new e-invoicing, continuous transaction control (CTC), or e-reporting requirements in other countries.

A centralized compliance architecture can help companies manage these requirements more efficiently. Instead of developing and maintaining a separate integration with each tax authority, businesses can use a common infrastructure to connect their ERP systems with multiple national e-invoicing and tax reporting platforms.

How Can EDICOM Help Businesses Comply with KSeF in Poland?

EDICOM provides an electronic invoicing and tax compliance platform designed to automate document exchange between businesses, their ERP systems, and tax authorities.

For KSeF compliance in Poland, EDICOM can integrate with a company’s ERP or accounting systems to retrieve invoice data, transform it into the structured format required by KSeF, and manage electronic communication with Poland’s National E-Invoicing System.

The integration can also return KSeF responses, invoice statuses, and relevant identifiers to the company’s internal systems. This helps finance and accounting teams maintain consistent, up-to-date information throughout the entire invoice lifecycle while reducing the need for manual processing.

For multinational organizations, the same approach can support e-invoicing and tax compliance requirements across multiple countries through a common infrastructure. This reduces the need to build and maintain isolated compliance projects and point-to-point integrations for every jurisdiction.

As mandatory e-invoicing and digital tax reporting continue to expand worldwide, a centralized approach can help companies turn regulatory compliance into a more automated, standardized, and scalable global process.