Cash Group is a cooperation of the four largest German private banks (Deutsche Bank, Commerzbank, HypoVereinsbank, and Postbank) and their subsidiaries, in which they mutually waive ATM usage fees for their customers. It is not an interbank network but uses the pre-existing girocard network. With more than 7000 ATMs, the cooperating banks' ATM networks form the third largest ATM network in Germany.