Its implementation requires not only technological adjustments, but also the streamlining of internal organisational processes and a clear assignment of responsibilities within the company.
KSeF – a central pillar of digital transformation
There is a reason why so much attention is currently being given to the National e‑Invoicing System. Its impact on day‑to‑day business operations extends far beyond the technical method of issuing invoices. Correct invoicing in the new format is essential for enabling sales and ensuring timely inflows of receivables. Meanwhile, access to invoices is necessary for settling liabilities on time and maintaining continuity in the supply of goods and services.
It is also important to note that a structured invoice is no longer a document sent directly from the seller to the buyer. First, it is transmitted to a central government system, where it receives a unique identification number (KSeF number). Only then can it be downloaded by the recipient. This means that tax authorities gain near‑instant insight into each transaction without having to wait for the monthly VAT return.
Companies’ readiness for KSeF
Preparation for KSeF is a complex undertaking that demands substantive, technological, and organisational efforts. According to Grant Thornton’s report “Opinions of entrepreneurs one month after KSeF went live” „Opinie przedsiębiorców miesiąc po wejściu w życie KSeF” (only in polish) fewer than 20% of companies declare full readiness, while almost 60% consider themselves largely prepared but still missing some elements. The remaining businesses report low readiness or none.
It is worth noting that, during the transition period, the government has postponed penalties for technical and formal errors until 2027. However, this grace period applies only to technical issues. Companies must st ill ensure accurate and reliable recording of transactions in their accounting books.
Important
The method of invoice posting directly affects the correctness of VAT reporting. All purchase and sales invoices appear in the monthly JPK_VAT file, and the responsibility for proper reporting has not been suspended.
How to verify the authenticity of invoices in KSeF?
An invoice issued outside KSeF is no longer recognised as valid documentation of a sales transaction. At the same time, the mere presence of an invoice in the system does not confirm its correctness or legitimacy. This creates one of the first practical challenges for companies. Public discussions have highlighted the risk that firms or public institutions might be “flooded” with invoices simply by misusing their tax ID (NIP).
In response, the Ministry of Finance has introduced the option for buyers to report “scam invoices” (documents reflecting fictitious transactions) directly through the KSeF application. However, this does not eliminate the risk of abuse—whether intended to fraudulently obtain payments or simply as a prank.
Important
Companies therefore need to implement clear invoice verification procedures. Every received invoice must be reviewed and approved by an authorised employee before being posted in the accounts and processed for payment.
Hopefully, in the initial period of KSeF implementation, tax authorities will take a flexible and pragmatic approach to irregularities. The scale of the reform is significant, and both businesses and the tax administration are facing new operational challenges and increasing volumes of questions and uncertainties.
The implementation of KSeF demonstrates that digitalising accounting is not just about changing how invoices are issued. It represents a broader redesign of everyday tax and financial processes. A company’s readiness for KSeF therefore requires attention to numerous details—from correct and timely transaction posting, through robust document verification procedures, to a well‑defined system of user permissions and efficient internal information flow. It is the sum of these seemingly minor elements that determines whether an organisation can operate smoothly in the new environment.
More insights into the challenges of accounting digitalisation can be found in the “New Digital Obligations in the Company” article series on the Grant Thornton website.
- New digital obligations for businesses: KSeF, JPK CIT and emerging compliance challenges
- New digital obligations for businesses: The National e Invoicing System (KSeF)
- New digital obligations for businesses: JPK CIT
- New digital obligations for businesses: the biggest challenges related to digital accounting
KSeF – frequently asked questions
Why does KSeF have such a significant impact on how companies operate?
KSeF changes not only the method of issuing invoices, but also affects sales processes, document circulation, payments, and the timeliness of settlements. Tax authorities gain near‑real‑time visibility into transactions.
What new risks are associated with KSeF?
There is a possibility of receiving fake invoices issued to a company (e.g., based solely on its NIP). For this reason, organisations must implement document verification and approval procedures.
How can invoice authenticity be verified in KSeF?
Each invoice must be checked by an authorised employee before posting. If an invoice does not reflect an actual transaction, companies can report a “scam invoice” in the KSeF application.
What does real readiness for KSeF mean?
It goes beyond implementing IT tools. True readiness involves streamlined processes—accurate invoice posting, a robust approval workflow, clear permission structures, and efficient internal communication.