Update of API for National e-Invoice System and Taxpayer Application KSeF in production environment

• API Krajowego Systemu e-Faktur and Aplikacji Podatnika KSeF will be updated on the production environment on December 4, 2023, from 13:00 to 20:00.
• The update includes changes to the document structure, query invoice detail, authorization error fix, interface specification changes, optimization of invoice queries, and other improvements.
• The update also includes changes to the visualization of PDF e-Invoices, compatibility with API KSeF 2.0.3, error information presentation, and addition of an endpoint for returning the current version of the mobile application.
• Temporary access difficulties may occur during the update.
• Apologies for any inconvenience caused.

Source: podatki.gov.pl

Note that this post was (partially) written with the help of AI. It is always useful to review the original source material, and where needed to obtain (local) advice from a specialist.