United Internet AG is a German Internet services company. With 2.91 million DSL customer contracts, it is a leading ISP in Germany. It is headquartered in Montabaur, Rhineland-Palatinate. Since 2003, it is listed on the TecDAX. In its operating business, United Internet AG acts primarily via 1&1 Internet and is active in various countries (as of February 2014: Austria, Canada, France, Germany, Italy, Mexico, Poland, Spain, United Kingdom, and USA).United Internet operates its own Internet backbone with computer clusters at several Internet exchange points (DE-CIX, INXS, AMS-IX, LINX).In July 2008, United Internet AG acquired a 30% stake in Jimdo GmbH.