In taxation §5 InvStG constitutes the requirements for the calculation, reporting and publication of investment funds to be considered transparent. To avoid lump-sum taxation the effort in data procuring, validating and processing rises remarkably. Using the provided tools and applications is a great challenge for tax departments in investment companies. It requires the provision of technical and business resources, which then cannot be used for the department's actual purpose. calculo as an integrated software solution allows you to automatically calculate and document the taxation of investment funds - on time, legally compliant and audit-proof.