We would like to inform you about the update of the API version of the National e-Invoice System and the KSeF Taxpayer ApplicationOn May 25, 2023, from 1:00 pm to 2:00 pm, an update of the API of the National e-Invoice System and the Taxpayer’s Application KSeF is planned for the production environment.For this reason, there may be temporary difficulties in access to the environment.Sorry for the inconvenience.
Source: podatki.gov.pl