In business, revenue is income that a company receives from its normal business activities, usually from the sale of goods and services to customers. In many countries, such as the United Kingdom, revenue is referred to as turnover. Some companies receive revenue from interest, dividends or royalties paid to them by other companies. Revenue may refer to business income in general, or it may refer to the amount, in a monetary unit, received during a period of time, as in "Last year, Company X had revenue of $32 million."

Profits or net income generally imply total revenue minus total expenses in a given period. In accounting, revenue is often referred to as the "top line" due to its position on the income statement at the very top. This is to be contrasted with the "bottom line" which denotes net income.

For non-profit organizations, annual revenue may be referred to as gross receipts. This revenue includes donations from individuals and corporations, support from government agencies, income from activities related to the organization's mission, and income from fundraising activities, membership dues, and financial investments such as stock shares in companies. For government, revenue includes gross proceeds from income taxes on companies and individuals, excise duties, customs duties, other taxes, sales of goods and services, dividends and interest.

In general usage, revenue is income received by an organization in the form of cash or cash equivalents. Sales revenue or revenues is income received from selling goods or services over a period of time. Tax revenue is income that a government receives from taxpayers.

In more formal usage, revenue is a calculation or estimation of periodic income based on a particular standard accounting practice or the rules established by a government or government agency. Two common accounting methods, cash basis accounting and accrual basis accounting, do not use the same process for measuring revenue. Corporations that offer shares for sale to the public are usually required by law to report revenue based on generally accepted accounting principles or International Financial Reporting Standards.

In a double-entry bookkeeping system, revenue accounts are general ledger accounts that are summarized periodically under the heading Revenue or Revenues on an income statement. Revenue account names describe the type of revenue, such as "Repair service revenue", "Rent revenue earned" or "Sales".