From 1.01.2018 the new version of JPK_VAT (Scheme 3) will be applied.  The test environment will be modified to accept the JPK_VAT version 3 files at the turn of the last days of November-the first days of December 2017. Version 3 JPK_VAT disappeared the key field "Kodsystemowy" from the header specifying what kind of message is being sent.  On 13.11.2017, a new version of the JPK_VAT file structure was revised and released, in which the "KodSystemowy" field was missing.