Documents needed to cancel contract - leaving germany

Hi,

I recently decided that I would sooner rather than later be leaving germany (in 1 month time) and would like to know what are the relevant documents needed to cancel my contract. And what is this 3 month fee, is it possible to give an estimate of how much it would cost?

TIA,
rrmz

Edit by o2_Katja: Verschoben von Mobilfunk in unsere Englisch Community