@sayandip2009 

Hello and welcome to our community

To cancel your DSL contract just follow these steps on this page: https://www.telekom.de/hilfe/vertrag-meine-daten/kuendigung/kuendigung-festnetz/kuendigungsgrund

If you can't understand everything, a Telekom employee can call you if you like.

Then you need to paste your customer number ("Kundennummer") and your preferred callback telephone number ("Rückrufnummer") here: 

https://telekomhilft.telekom.de/t5/user/myprofilepage/tab/personal-profile%3Atelekom-custom-user-profile-userdata

Click on "Sichern" after you entered your details.

sayandip2009

Hello, sorry to type in English.  I want to cancel my Telekom contract from 31.08.2019 since I am leaving Germany. Do I have to submit anything else?

I guess it is not sufficient to declare a wish to terminate your contract in this forum.

You will have to submit a "Kündigung wegen Umzug ins Ausland" (termination of contract due to moving abroad). You can do this online here and, according to this page (German language only, sorry for that), termination is accepted with six working days notice if you terminate due to the special cause of moving abroad. Telekom wants to see proof that you are indeed moving. As examples of acceptable proof they list the following:

- Abmeldebescheinigung from the Einwohnermeldeamt

- statement from employer

- military deployment orders