Expenses of running a business, or operating expenses, refer to the costs that are necessary for running operations and generating revenue. These expenses can include overhead such as rent and utilities; wages for employees; insurance for business operations; office supplies; and advertising expenses. While some businesses may incur additional costs depending on their industry, most companies will need to pay these common expenses in order to successfully run and grow their business. With careful assessment and budgeting, entrepreneurs can minimize unnecessary expenditures and maximize their returns.