1&1 AG is a leading telecommunications provider in Germany, headquartered in Montabaur, Rhineland-Palatinate. Established in 1988, the company was originally known as 1&1 Internet AG and later rebranded as 1&1 Drillisch AG in 2017. In June 2021, it adopted the name 1&1 AG. It is a subsidiary of United Internet AG, holding a majority stake of 78.32% as of April 2022.