Convenience for companies in Polen
KSeF in eFaktura.nl
Issue and receive invoices via the National e-Invoicing System.
Convenience for companies in Polen
KSeF in eFaktura.nl
Issue and receive invoices via the National e-Invoicing System.
DIGITAL TRANSFORMATION IN INVOICING
A central system that organizes invoicing in Poland.
What is KSeF?
KSeF (National e-Invoicing System) is a central platform of the Ministry of Finance that enables issuing, sending, and receiving invoices in a structured electronic format. Each invoice is sent directly to the tax system and receives a unique identification number.
KSeF is part of the digitalization of the Polish tax administration and aims to simplify settlements, increase document accuracy control, and reduce errors and VAT fraud.
From April 2026, using KSeF is mandatory for all companies registered in Poland – including those operating abroad.
E-INVOICES FOR POLISH COMPANIES
KSeF introduces new obligations for businesses
To use KSeF, an Excel invoice or a PDF sent by email is not enough. You need
a tool that provides full support for e-invoicing within the National e-Invoicing System.
What does this mean in practice?
Issuing KSeF-compliant invoices
You need a tool that ensures full support for e-invoicing in KSeF.
Sending and receiving invoices in KSeF
Secure transmission of invoices directly to KSeF and receiving invoices issued by other contractors.
Compliance with regulations and digital standards
Invoices compliant with Polish tax law and EU requirements, structured documentation, and adherence to KSeF rules.
INVOICING AS FLEXIBLE AS YOU
KSeF and working abroad under A1
KSeF is mandatory for all Polish companies – including those operating abroad under the A1 certificate.
In the European Union, Peppol is being gradually implemented – already mandatory in Belgium and gaining importance in other countries. Polish companies are not formally required to use Peppol, but in practice Belgian clients often expect it, and the standard is becoming more common across the EU.
That’s why in eFaktura.nl you can use both KSeF and Peppol – in one system, without format issues.
ALL IN ONE PLACE
Meet KSeF requirements and invoice with ease
The eFaktura.nl application supports invoicing in KSeF, ensuring compliance with Polish regulations and European digital standards. The system automates sending and receiving e-invoices and organizes document flow, also for companies operating abroad.
How does sending an invoice to KSeF work in eFaktura.nl?
- The user creates an invoice in eFaktura.nl
In the standard invoicing form, select the option: Send to KSeF. - eFaktura.nl sends the invoice to KSeF
The document is automatically transmitted to KSeF in a structured XML format. - KSeF assigns a number and confirms receipt
eFaktura.nl receives the confirmation and KSeF number, visible in the invoice status. - The invoice is delivered to the recipient
The invoice is available in the recipient’s KSeF and ready for payment. - The invoice can also be sent via system email as a PDF outside KSeF:
- to a foreign company, also via the Peppol network
- to a Polish company (informationally or as a payment reminder)
The entire process is automatic, fast, and compliant with KSeF, while additional channels allow delivery tailored to the recipient.
COST AUTOMATION
Receive purchase invoices
The integration also allows receiving purchase invoices.
When a contractor issues an invoice via KSeF, you will receive an automatic notification and the document will appear directly in the COSTS section. Thanks to the built-in converter, the e-invoice is displayed in a clear format.
How to connect to KSeF?
The certificate is used to authenticate your company in KSeF, confirming that actions (e.g. sending invoices) are performed on its behalf.
Obtaining a KSeF certificate
To generate and download a certificate, go to:
https://ksef.mf.gov.pl and log in, e.g. via Trusted Profile.
Then follow the instructions in the government system.
If needed, DOWNLOAD THE GUIDE.
Download certificate files
During certificate generation, two files will be saved:
certificate file
(.cert)
key file
(.key)
certificate file
(.cert)
key file
(.key)
You will also set a password for the certificate.
These files and password are required to connect to eFaktura.nl.
Grant KSeF permissions
Go to KSeF settings in eFaktura.nl
Log in and navigate to: Settings → KSeF
Verify company details
Confirm your VAT ID and that you act on behalf of your company.
Add certificate
Upload (.cert) and (.key) files and enter the password.
Done
Your eFaktura.nl account is now connected to KSeF.
BENEFITS OF THE CHANGE
What are the benefits of using KSeF in eFaktura.nl?
KSeF changes invoicing, but in eFaktura.nl it does not disrupt your daily workflow. After one-time integration, you issue invoices as before, while the system ensures compliance.
Order and compliance
Invoices comply with Polish tax law and EU requirements. Documents are stored in one central system, improving accounting and reducing audit risks.
Fewer errors, fewer corrections
Data is automatically validated by the system. No more manual corrections or back-and-forth with accounting.
No change to daily work
After integration, the eFaktura.nl interface remains simple. You issue invoices as usual, while the system handles formatting and delivery.
Flexibility for international work
KSeF meets Polish requirements, while eFaktura.nl also supports Peppol. This supports A1 businesses and international clients across Europe.
One tool instead of many
In eFaktura.nl you manage KSeF, Peppol, sales and purchase invoices in one system. No need for additional tools or process changes.
Support at every stage
We provide full support – from integration to daily use. Over time, KSeF becomes a natural part of your workflow.
Frequently Asked Questions (FAQ)
Using KSeF in eFaktura.nl is included in your selected plan. There are no additional fees for sending or receiving e-invoices via KSeF.
KSeF integration is available only for paid users. If you purchase a subscription during the free trial, your first payment will be reduced proportionally based on the unused trial days.
KSeF is mandatory for all companies registered in Poland, including those providing services abroad (e.g. under the A1 certificate).
Working under A1 does not exempt you from KSeF. A1 relates to social security, while KSeF regulates invoicing and tax obligations in Poland. Companies operating under A1 must also use KSeF.
According to Polish regulations, companies are not required to use Peppol. In practice, however, foreign contractors (e.g. in Belgium) may require invoices in this format, and eFaktura.nl allows you to use both KSeF and Peppol simultaneously.
In eFaktura.nl, you can use both KSeF and Peppol in one system, without changing your workflow or paying additional fees.
If your company is registered in Poland, the invoice must first be issued and registered in KSeF. Only after it is accepted and assigned a KSeF number can it be sent to a foreign contractor via Peppol.
Not using KSeF may result in tax settlement issues, risk of penalties, and difficulties working with your accountant. KSeF is the central invoicing system in Poland, and not using it means failing to meet tax obligations.
Once an invoice is registered in KSeF, it cannot be edited. If there is an error, a correction invoice must be issued in accordance with applicable regulations.
KSeF is a system for registering and exchanging invoices. However, payment reminders can be sent directly from eFaktura.nl.
Although the invoice is sent to KSeF in XML format, in eFaktura.nl you can view and work with it in a user-friendly format.
If you encounter a problem during KSeF integration in eFaktura.nl or have questions, contact our support team via the in-app chat.
If the issue occurs during login to KSeF, certificate generation, or other actions performed directly in the KSeF portal, we recommend contacting the Ministry of Finance support.
After a one-time integration, the eFaktura.nl form remains just as simple, while the system ensures correctness, formatting, and compliance in the background.
eFaktura.nl guides you through the entire process step by step. The system is easy to use, and we provide full support, including help with your first invoices – also with KSeF and Peppol.
