National e-Invoicing System (KSeF)

The National e-Invoice System (KSeF) introduced by the Ministry of Finance is a nationwide IT system in which businesses will be required to issue and receive electronic structured invoices. The system is designed to build a unified, central register of electronic invoices, standardize files and reduce the cost of processing accounting documentation. The documents will be stored there for 10 years.

KSeF – since when?

The use of KSeF is to be mandatory from:

Effective date of mandatory KSeF What entity is required to use the KSeF?
July 1, 2024 Active VAT payers
January 1, 2025 Taxpayers who are exempt from VAT (non-taxpayers)

How does the system work?

The National e-Invoice System (KSeF) allows structured invoices to be issued in XML format using integrated financial and accounting software. The KSeF system checks whether the document complies with the standard (the correct XML schema of the invoice) and assigns it a unique number. The issuer receives an official certificate of receipt (UPO). The invoice recipient gains access to the invoice by authenticating himself in KSeF or by providing certain invoice data (so-called anonymous access).

With the entry of KSeF, will paper invoices disappear from circulation?

Despite the fact that digitization is on a higher level every year, paper invoices will not disappear, although there will be fewer and fewer of them over time. Paper invoices (but also some of their electronic counterparts that do not meet MF requirements) would disappear definitively if the National e-Invoice System became fully mandatory for everyone. It is worth noting at this point that KSeF will not include:

  • consumer invoices (so-called B2C),
  • Tickets that are considered invoices including receipts on toll highways,
  • invoices issued under the OSS and IOSS procedures.

What is the process of preparing sales invoices in KSeF?

The process of preparing sales invoices in KSeF consists of the following steps:

  1. Substantive preparation of the invoice.
    This includes specifying all the required and optional fields of the invoice schema, such as the buyer’s name and address, seller’s data, description of goods or services, net amount, VAT rate, VAT amount and gross amount.
  2. Technical preparation of the invoice.
    It involves the creation of an XML file containing invoice data in a format compatible with the KSeF schema.
  3. User authorization in KSeF.
    A user who is to issue invoices in KSeF must be authorized to do so.
  4. Sending an invoice to KSeF.
  5. Validation of the invoice and its acceptance into KSeF.
    Once the invoice is sent to KSeF, it will be verified for correct format and content. If the invoice is correct, it will be accepted into KSeF and assigned a reference number.
  6. Assigning a reference number.
    The reference number is a unique identifier of the invoice in KSeF. The reference number can be used to search for an invoice in KSeF.

How to join the KSeF?

Joining the National e-Invoicing System (KSeF) is currently voluntary, but it will be introduced as a mandatory solution for the first taxpayers in July 2024. In order to join KSeF, it is necessary to have a qualified electronic signature, a qualified electronic seal, a trusted signature or a token generated by the National e-Invoicing System. Then the entry into the KSeF system is done for the first time through the government site.

Is it possible to self-invoice in KSeF?

The taxpayer (vendor) has full ownership rights in the National e-Invoice System (KSeF). Among other things, these authorizations allow him to grant further rights to entities and individuals in KSeF, making it possible, for example, to designate entities that can issue invoices in the self-invoicing procedure as buyers.

What should be understood as the date of issue in KSeF?

According to Art. 106na para. 1 of the VAT Regulations, a structured invoice is considered to have been issued on the date it is uploaded to the National e-Invoice System. This means that the date an invoice is generated in the internal invoicing system is not the same as the fact that it was issued. This is very important because a VAT invoice that is not issued in KSeF after June 30, 2024 will not be an accounting document.

An important field in the XML structure of a structured invoice is P_1, which refers to the invoice date. This field must be filled in when the invoice is sent to KSeF.

The Finance Ministry’s Q&A on the KSeF raised an important point related to the P_1 field:
“The date given in field P_1 is the invoice issuer’s indicated date. The fact that the P_1 field indicates a different date than the date of sending the invoice to KSeF will not cause the system to reject the invoice. In this case, according to Art. 106na para. 1 of the VAT Regulations it is assumed that the invoice was issued on the date it was sent to KSeF, even though a different date was indicated in the P_1 field.“.

VAT deduction on invoices issued in KSeF

In order for the purchaser to realize his right to deduct VAT, he must have an invoice. Thus, the purchaser will realize the right to deduct VAT no earlier than in the settlement for the period (month) in which he received the invoice or customs document.

According to Art. 106na para. 3 of the VAT Regulations, a structured invoice is considered to have been received using KSeF on the date the number identifying that invoice is assigned in this system.

The moment of assigning an identification number to an invoice issued in the KSeF system will be at the same time the moment of receipt of the structured invoice by the recipient. Only at this point – in the settlement for the month in which the invoice was received – will the buyer have the right to deduct the VAT from the structured invoice.

How to access the KSeF?

Two ways of granting, changing or revoking authorizations are provided:

  1. electronically – using interface software ( – the taxpayer or other authorized entity indicates the required range of data, in order to grant, change or revoke authorizations.
  2. in paper form by submitting to the appropriate head of the tax office a notice of granting or revoking authorization (ZAW-FA) to use the National e-Invoice System.

The ability to grant or revoke authority to use KSeF in paper form is provided for taxpayers and entities that are not individuals and do not have the ability to authenticate with a qualified electronic seal.

In the case of taxpayers who are individuals, the original power of ownership is automatically assigned. Such a person does not have to report anything. The system can be accessed by authorizing oneself with a Trusted Signature or a qualified electronic signature.

Taxpayers who are not individuals and have an electronic qualified stamp containing the company’s NIP number, can use KSeF on the basis of primary ownership without reporting it to the tax office. In other cases such company, in order to use the KSeF, must, through the ZAW-FA notice, designate an individual entitled to use the KSeF. That person will also have the ability to grant further authorizations electronically within the system.

Instructions for authentication in the KSeF Taxpayer Application.

Template of notification on granting or revoking rights – ZAW-FA

How will KSeF affect cooperation with an accounting office?

As it will be necessary to verify the existence of each cost invoice in KSeF and verify the dates of issuance and receipt in order to properly account for the cost invoices, it will be necessary to grant us access to your invoices in the system. KSeF allows you to grant both invoice issuance and read-only access. To cooperate with us, you only need to grant us read-only access – as per the instruction. We must receive access to your data in KSeF by 30.06.2023 at the latest.

KSeF – useful information

User’s Guide – KSeF Taxpayer Application

Logging into the KSeF Taxpayer Application.

KSeF – questions and answers