It took its current name after Deutsche Telekom's German consumer fixed-line unit T-Home was merged into T-Mobile Deutschland.

[2] Germany's first mobile-communications services were radiotelephone systems that were owned and operated by the state postal monopoly, Deutsche Bundespost.

[5][6] On 1 July 1992, it began to operate Germany's first GSM network under the name De.Te.Mobil Deutsche Telekom Mobilfunk GmbH.

[7] This deregulation of the German telecommunications industry continued in November 1996, when DT was privatized and had the largest European IPO at the time, with the stock abbreviation 'DT 1'.

On 5 April 2011, LTE was launched in the Call & Surf via Funk tariff which was intended as a DSL alternative for areas which have limited fixed-line speeds.

Cologne became the first city in which Telekom enabled the 1800 MHz frequency of LTE, with service launched on 1 June 2010.

[12] On 17 June 2014, Telekom announced that they would not charge for LTE roaming in Belgium, France, Italy, Norway, Poland, Spain, or the United Kingdom.