An implicit cost is any cost that has already occurred but not necessarily shown or reported as a separate expense. It represents an opportunity cost that arises when a company uses internal resources toward a project without any explicit compensation for the utilization of resources. This means when a company allocates its resources, it always forgoes the ability to earn money off the use of the resources elsewhere, so there's no exchange of cash. Put simply, an implicit cost comes from the use of an asset, rather than renting or buying it.