Yes, but only during the transition period and in strictly defined cases. From 1 February 2026 large companies must use KSeF, and from 1 April 2026 all other taxpayers. Until the end of 2026, exceptions remain – e.g. invoices up to PLN 10,000 per month, fiscal receipts treated as invoices, or documents from taxpayers entering the system later. This means that in 2026 companies in Poland will run two processes, but from 1 January 2027 the obligation becomes universal.