Are there any documentations necessary to verify a German account?

You will require two documents; one showing proof of address and another showing proof of identity. So, you will be required to have a Stromrechnung sourced from major providers such as E.ON, Innogy, RWE, and Uniper among others. Secondly, you will need a Telefonrechnung sourced from T-mobil or your ideal provide. Lastly, you will be required to have your Ausweis and a local phone number.