It depends on whether you opted for a 2-year contract or a contract with 4 weeks' notice to the end of the month.



If you have chosen a contract with 4 weeks notice to the end of the month, no special documents are needed. You just have to cancel in text form in due time. Address see top of your invoice.



If you have chosen a 2-year-contract and you leave Germany before your contract ends regularly, you may cancel your contract with a notice period of 3 months to the end of the month. This notice period starts from the day you move abroad. For the required documents and data you can orient yourself on this form (there is no special form for DSL contracts).

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Thank you @blablup,



Since I have a 2-year contract I guess I will use the form you linked to but replace "mobile phone" with DSL in appropriate places.

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