InnerSource is the application of best open source practices within the walls of the organization. Large corporations are required to be more and more efficient in the development of software and even more in the banking industry. There are three main areas of expenditure: infrastructure and facilities, people, and technology. The latter is of importance nowadays as key for the business and core to this paper. Reusability and collaboration are some of the ways a large corporation can be more efficient in technology. By being able to discover existing software and collaborating across business units, departments, or even geographical regions, corporations can share effort across them, and avoid starting once and again a similar piece of software.