In which language is the European certificate of conformity written to be valid for registration?

Manufacturer chooses language of certificate of conformity. Usually language is language of main manufacturer. For example, Fiat is Italian, so, language of certificate of conformity is Italian ; Renault is french manufacturer so, language for renault certificate of conformity is French ; Jaguar is English manufacturer, so, Jaguar certificate of conformity is English document....etc.....

What you have to know about European certificate of conformity is :

• It's an European document valid accross all European countries.
• Document is unique and valid for one vehicle identification number (VIN)
• Certificate of conformity has to be printed on watermark paper