KSeF: National System of e-Invoices in Poland

Comarch EDI Ready for Obligatory
e-Invoicing in Poland!

Learn how you can send & receive structured invoices to/from the National System of e-Invoices (KSeF) using our platform

One Solution to Manage e-Invoice Exchange with Multiple Partners in Multiple Countries

As a global supplier of systems and services for exchanging electronic documents, Comarch has extensive experience in optimizing the Accounts Payable (AP) and Accounts Receivable (AR) processes.

For years, we’ve been providing support to companies operating both in countries where e-invoicing has already become obligatory (such as France, Spain, Germany, Turkey, and Italy) and places where such an obligation is to be introduced (e.g., in Poland, where, according to the announcement of the Polish Ministry of Finance, the e-invoicing mechanism will be based on the Italian solution).

It means that with Comarch EDI, you can exchange documents with multiple partners from all over the world using just one tool without worrying about the new and upcoming policies. 


Global e-invoicing experience

What is the National System of e-Invoices

The National System of e-Invoices (KSeF) is a data exchange system for issuing, receiving, and storing structured invoices. It is also used for marking invoices with an identifying number, as well as checking whether one’s invoices are compliant with a specific pattern.

See the infographic about KSeF

E-Invoicing to Become Obligatory in Poland in 2024!

On January 1, 2022, the National System of e-Invoices has been introduced in Poland as a voluntary solution. The Polish Ministry of Finance wants KSeF to become an obligatory solution in 2024 and electronic invoicing to become mandatory for all taxpayers in the same year.

Therefore, Poland is now becoming yet another country that belongs to the European Union (after Spain, Portugal, and Italy), which has decided to change the model of electronic invoice processing from the post-audit model to the clearance model.

The Timeline

National System of e-Invoices in Poland

Prepare your company for the National System of e-Invoices (KSeF)

Become Fully Compliant with KSeF via Comarch EDI

Being an operator of electronic document exchange (including e-invoices), Comarch constantly monitors legislative changes in Polish law.

We are very much involved in the KSeF pilot project. Our specialists are present at meetings during which the technical details of the system, the specification of a structured invoice, and API documentation are discussed.

The API interface is to enable the integration of Comarch EDI (used by thousands of customers in Poland and abroad) with the National System of e-Invoices.

This means that it will be possible for all users of our platform to send and receive e-invoices to/from KSeF. Comarch EDI will also ensure full compliance with the latest legal regulations and transparency of the flow of all invoices (and their statuses).

Learn more about Comarch EDI

What does the integration of Comarch EDI with KSeF look like?

What does the integration of Comarch EDI with KSeF look like

What Will You Gain Thanks to the Integration of Comarch EDI with KSeF?

  • Challenge 1#

    All invoices must be structured and compliant with the KSeF


    Comarch will take care of adjusting the format in which you send your invoices to the requirements imposed by KSeF. You don't have to waste time to manually adjust each invoice.

  • Challange 2#

    My customers and suppliers have different requirements as to the information included on the e-invoices. Aside from verifying whether the documents are compliant with KSeF specification, I also need business validation to meet also my partners’ expectations.


    With Comarch, you can maintain the validation of multi-document processes. Thanks to this, you will be sure that all the required information is included in the invoice, even if the KSeF does not require it.

  • Challange 3#

    I want to have access to all of my documents any time I want to export an invoice that was previously registered in KSeF - together with all its history of statuses. 


    Comarch allows you to store KSeF XML invoices together with the history of KSeF statuses, invoice identification number or UPO (confirmation).

  • Challange 4#

    I want the system to be operated by true specialists with a lot of experience in similar projects.


    Comarch has many years of experience in carrying out electronic documents exchange projects, which often include the management of processes related to sending and receiving documents to/from governmental institutions in many countries.


    After the official launch of the National System of e-Invoices in Poland, Comarch EDI users will be able to choose one of two models by which our solution will be connected to the government platform. The first one involves the exchange of e-invoices along with basic validation (making sure that invoices are fully compliant with the KSEF requirements). The second model includes the so-called business validation required by the contractor. You can find detailed diagrams of both models below.

    A Scheme of the General Model

    A Scheme for Sending an Invoice to KSEF after Validation of the "Pre-invoice"

    What is a structured invoice

    As described in the Act on amending the Act on tax on goods and services (and several other acts) adopted by the Sejm of the Republic of Poland:

    "A structured invoice is issued and received via the National System of e-Invoices using an interface software, it has an electronic form and is created in accordance with a provided template…”

    A structured invoice is to be presented in the XML format according to the logical structure of e-Invoices (FA_VAT). Therefore, it is the third type of invoice next to the paper and electronic invoices. It is issued by taxpayers using the KSeF system and marked with a number identifying this invoice in the system.

    Structured invoices will be issued according to a template based on the logical structure presented by the Ministry of Finance.

    What is a structured invoice?

    How is KSEF supposed to work in Poland?

    Access to the National System of e-Invoices may be obtained by a taxpayer, an authorized person, an authorized entity, or one of the entities referred to in Article 106c of the Act, provided they are allowed to issue (or access) structured invoices.

    The legislator is to provide the possibility of issuing a structured invoice directly in the system (via a web interface) or via the taxpayer's financial and accounting system in accordance with the published template.

    When invoices are issued in the taxpayer's financial and accounting system, the documents should be delivered to KSEF via a defined connection, e.g., via EDI to KSeF API.

    How is KSEF supposed to work?

    Characteristics of the e-invoicing in Poland

    • Not mandatory for B2G or B2B transactions yet. However, since 2019, public institutions have been obliged to receive e-invoices from their suppliers if they wish to send them in such form.
    • In regard to B2B transactions, from October to December 2021, a pilot project with the participation of taxpayers was carried out.
    • Since January 1st 2022, the National System of e-Invoices (KSeF) has been operating as a voluntary solution. From that moment on, it has been possible to issue structured invoices under the KSeF.
    • The National e-Invoice System will become an obligatory solution in 2024.

    E-invoice format and platform

    • The required invoice format is XML.
    • For the issuance of invoices to public authorities, a special e-invoicing platform was provided: the PEF portal (Platforma Elektronicznego Fakturowania).
    • National e-invoicing system named Krajowy System e-Faktur (KSeF)
    • It is worth mentioning that, in the optional version of the KSeF, both systems (KSeF and PEF) will always be independent.

    E-invoicing process description

    E-invoices covering B2B transactions will be prepared in taxpayers’ ERP systems or via dedicated platform for micro-businesses. After delivery to KSeF, e-invoices will be timestamped and assigned a unique identification number (KSeF ID) and an official confirmation of receipt (Urzędowe Poświadczenie Odbioru – UPO) is returned to the invoice issuer. Only then does the invoice become valid.

    Integrity and authenticity

    To ensure integrity and authenticity of e-invoices, any method is accepted, such as Qualified Electronic Signature. Data sealed with a qualified electronic seal enjoy the presumption of integrity and authenticity.


    Storage period 5 + 1 years.

    What is KSeF - FAQ

    For more information about what is KSeF, when it will become mandatory and who has to issue structured invoices, check our Questions and Answers.

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