Poland is introducing mandatory electronic invoicing under a Continuous Transaction Controls (CTC) model. From 2026, VAT-registered businesses must issue invoices through the national platform, KSeF (Krajowy System e-Faktur).
The mandate will apply to domestic B2B transactions and will gradually replace existing processes, including parts of the public-sector invoicing framework.
This blog explains the timeline, scope, formats, transitional rules, penalties, KSeF 2.0 updates, and what businesses should prepare for.
Why Poland Is Introducing Mandatory E-Invoicing
Like several other European countries, Poland has chosen a CTC model to strengthen VAT reporting and reduce fraud.
CTC stands for Continuous Transaction Controls. It means that invoices must pass through a government platform for approval before they are considered valid.
The purpose is to:
- Increase transparency
- Improve VAT reporting efficiency
- Reduce VAT fraud
- Ensure VAT revenues are correct and timely
Under this system, invoices are time-stamped and controlled centrally by the Ministry of Finance.
What Is KSeF?
KSeF stands for Krajowy System e-Faktur, which translates to the National E-Invoice System.
It is Poland’s central e-invoicing platform used to:
- Approve invoices
- Exchange B2B invoices
- Handle public-sector invoicing
KSeF operates under the CTC framework, meaning invoices must be submitted to the platform for clearance.
The required invoice format in KSeF is FA_VAT, an XML-based structured format.
Timeline for Mandatory E-Invoicing in Poland
On April 26, 2024, the Polish Ministry of Finance announced the implementation timeline for mandatory e-invoicing, which has been in effect since February 1, 2026.
February 1, 2026 – Large Businesses
Mandatory for VAT-registered businesses with turnover exceeding PLN 200 million (approximately $54 million).
These companies must issue invoices through KSeF.
April 1, 2026 – All Remaining Businesses
Mandatory for all other VAT-registered businesses in Poland.
From this date, mandatory e-invoicing applies to all domestic B2B transactions.
Date
Who Is Affected
Obligation
February 1, 2026
Businesses with turnover > PLN 200 million
Mandatory B2B e-invoicing via KSeF
April 1, 2026
All remaining VAT-registered businesses
Mandatory B2B e-invoicing via KSeF
2026 (Transitional Year)
All businesses
Education-focused enforcement period
January 1, 2027
All businesses
KSeF-specific sanctions apply
Who Must Register E-Invoices in KSeF?
The new rules apply to VAT-registered businesses in Poland, including certain foreign entities.
- Polish Companies Issuing Domestic Invoices – YES
If one Polish company issues an invoice to another Polish company, and both have a Polish VAT number, the invoice must be registered in KSeF.
- Foreign Headquarters with a Polish Branch – YES
If a foreign company has a branch in Poland with a Polish VAT registration and issues invoices to another Polish company, those invoices must be registered in KSeF.
- Polish VAT Number Supplying Foreign Companies – YES
If a company has a Polish VAT number and operates in Poland, and supplies goods or services to a foreign company without a Polish VAT number, the invoice must still be registered in KSeF.
- Foreign Company Without Polish VAT Registration – NO
If a foreign company without a Polish VAT registration issues invoices to a Polish VAT-registered company, those invoices do not need to be registered in KSeF.
Scenario
Polish VAT Number
KSeF Required?
Polish company invoicing another Polish company
Yes
Yes
Foreign HQ with Polish branch issuing domestic invoices
Yes
Yes
Polish VAT-registered company invoicing foreign company
Yes
Yes
Foreign company without Polish VAT registration
No
No
Transitional Period and Penalties
Poland has introduced a transitional year during the rollout of mandatory KSeF e-invoicing.
Transitional Year – 2026
Although mandatory e-invoicing begins in February and April 2026, the year 2026 is considered a transition period. Small businesses may continue using paper or other electronic invoices until September 30, 2026. Offline mode is allowed until December 31, 2026 if connectivity to KSeF is unavailable. During 2026, the authorities emphasize education and transition.
Penalties From 2027
From January 1, 2027, KSeF-specific sanctions will apply. The exact penalty amounts are defined in implementing acts.
B2G E-Invoicing in Poland
- Since 2019: All public-sector invoices (B2G) must be issued through PEF (Peppol).
- Full Rollout in 2026: From 2026, KSeF becomes the primary platform for public-sector invoicing. The PEF platform will remain available, but KSeF will be the preferred channel.
Archiving and Retention Requirements
Poland has clear archiving rules for electronic invoices.
- Retention period: 10 years
- Storage: Allowed anywhere in the EU, provided tax authorities have online access
- KSeF automatically retains invoices for 10 years at no additional cost
Companies should ensure internal compliance processes align with these requirements.
Official KSeF 2.0 Timeline
The Polish Ministry of Finance has published the following implementation schedule for KSeF 2.0:
- September 30 – KSeF 2.0 test environment opened
- October 15 – Pre-production (demo) environment available
- November 1 – KSeF certificates available for download
- January 26 – Production KSeF 1.0 shuts down (technical break)
- February 1 – KSeF 2.0 production goes live
Full end-to-end testing in production cannot be completed before February 1, as the production environment does not exist earlier.
What Businesses Should Do Now
Companies operating in Poland should:
- Confirm whether they fall within scope
- Ensure systems can generate FA_VAT XML invoices
- Prepare integration with KSeF
- Review authorization processes under KSeF 2.0
- Understand transitional rules and sanction timelines
Frequently Asked Questions About E-Invoicing in Poland
KSeF is Poland’s National E-Invoice System used to approve and exchange electronic invoices under the CTC framework.
Yes. It is mandatory since February 2026.
From February 1, 2026 for businesses with turnover exceeding PLN 200 million, and from April 1, 2026 for all remaining businesses.
Yes. TrueCommerce supports businesses in preparing for and complying with the Polish KSeF requirements.
We help ensure that invoice data is generated in the required FA_VAT format and transmitted through the KSeF platform in line with the mandatory timeline.
If you would like to understand how TrueCommerce can support your organization, you can contact our team for more information.
Invoices submitted to KSeF must use the FA_VAT XML format.
Sanctions begin from January 1, 2027 following the transitional year in 2026.