do I need speak german, when starting at your consultancy?

Ideally you should speak German. Even if most of our slides are in English, our clients are German and meetings are usually conducted in German. 
In rare instances we employee non-German speakers but they should then try to learn German ASAP (not easy) as otherwise they are limited in terms of which projects they can be staffed on. 

Also for Deloitte Consulting an advanced level of German (minimum B2) is necessary but it sometimes also depends on the position and the projects. Especially for entry level it's a must have as most of our onboarding and training sessions are in German. 

You can also find information about required language skills in every of our job postings. 

Since most of Mazars Germany's clients are based in Germany, or at least we are in contact with the subsidiaries in Germany, a basic knowledge of German is essential.

Everyone is welcome at Prokura - as our projects are focused all over Europe, it is possible to join us without any knowledge of German. However, it's certainly not a bad idea to learn German in order to be able to support our clients in the DACH region.

For TKMC, speaking German is also a must-have as it is needed for many projects.