From September 1, 2023, taxpayers no longer have to issue advance invoices if they receive all or part of the payment in the same month in which they made the delivery. One final invoice is enough. The purpose of the new regulations is to simplify settlements, but also to adapt to the requirements of the mandatory National e-Invoice System. From September 1, the correcting invoice must also contain the KSeF number of the corrected invoice.
Source Prawo.pl
