KSeF – new obligations and practical challenges for businesses in 2026

The implementation of KSeF has been associated with significant technical and organizational challenges, which resulted in the decision to postpone its mandatory application in Poland. The delay was primarily driven by the need to further refine technical solutions and ensure the stability of the system.

As of 1 February 2026, the obligation to issue structured invoices applies to large entities (whose turnover for 2024, including VAT, exceeded PLN 200 million), and as of 1 April 2026 to other taxpayers, except for the smallest so-called “digitally excluded” taxpayers, whose transactions involve relatively low values (up to PLN 10,000 of monthly turnover). For this group, the obligation will apply from 1 January 2027.

Operational Challenges and Process Adaptation

Experience from the first months of mandatory use of the system indicates that the key challenge lies not so much in the technology itself, but in adapting day-to-day operational processes. The implementation of KSeF requires significant changes in the functioning of accounting, sales, and IT departments, as well as a revision of document workflows and communication with counterparties.

In practice, businesses are facing the following challenges:

• System stability and process planning – during periods of increased workload, system availability may be limited, which requires appropriate process planning and moving away from issuing invoices shortly before deadlines.
• Handling of purchase invoices – it is necessary to ensure ongoing verification that invoices received from counterparties have been correctly issued in KSeF. Challenges arise particularly in relation to employee expenses and in cases where standardized purchase order numbers are not used in internal systems. In addition, increasing importance is attached to the verification of invoices that may not reflect actual transactions prior to their recognition in the accounting records (so-called “scam invoices”).
• Rejection of invoices and error handling – the system automatically rejects invoices containing structural or logical errors, which necessitates the implementation of procedures for their prompt identification, correction, and resubmission.
• Offline modes and business continuity – in the event of system unavailability, invoices may be issued in offline mode, subject to the obligation to submit them to KSeF within a specified timeframe. This requires the implementation of appropriate contingency procedures.
• Internal controls and data consistency – the implementation of KSeF requires the establishment of control mechanisms ensuring, in particular, the completeness and accuracy of data, consistency of invoices with underlying documentation, mitigation of the risk of duplicate postings, and correct reporting of KSeF identification numbers in records and JPK_V7 filings.

It should be noted that the current year serves as a transitional period during which the application of the regulations is not yet subject to financial penalties. As of 1 January 2027, however, their introduction is planned, which will materially increase the importance of proper KSeF implementation and the alignment of operational processes. This does not, however, relieve taxpayers from the obligation to ensure ongoing compliance with the new regulations and to maintain the accuracy of invoicing processes.
 

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