Hi Alan, unfortunately Germany is not that small to have all ZIPs on one list. Here is a URL that may be helpful: http://www.deutschepost.de/postdirekt/index.html?inhalt=/postdirekt/produkte/plzsuche.html There may be more than one ZIP for Biebrich related to the street you would like to write to but try 65203 Wiesbaden. The post office will probably forward it to the right place. Regards, Achim