We have all heard, "You have to spend money to make money." In business the money spent is often referred to as an expense. What is an expense? The IRS describes it as: "Business expenses are the cost of carrying on a trade or business. These expenses are usually deductible if the business operates to make a profit." If you spend money to operate your company it is most likely an expense. Some examples include: advertising expense, rent expense, wage expense, office supplies and interest expense. You want to increase income and reduce expenses.