The contact is a mandatory field in Candis and is therefore always sent to DATEV. However, this does not automatically mean that it must also be displayed in the "Buchungstext".
If your Buchungstext is missing in DATEV Kanzlei-Rechnungswesen, then probably "Ware, Leistung" is specified instead of "Lieferantenname, Ort". You can change this setting at any time and save it.
In DATEV Unternehmen online you can define which information should be included in the "Buchungstext". To do this, go to:
Startseite Belege
"Stammdaten" in the right side menu
Rechnungsordner
In this menu we now see one or more folders. Among them there should be the folder "Eingangsrechnungen".
Mark the folder "Eingangsrechnungen"
Select the pencil icon to edit
Under "Buchungstext" you can now choose between "Lieferantenname, Ort" and "Ware, Leistung".
If "Ware, Leistung" is selected here, the field "Buchungstext" is transferred empty. This is due to the fact that Candis does not read out "Ware, Leistung" and therefore it is not transferred to DATEV.