The generally accepted accounting principles (GAAP) Revenue Recognition Guidelines outline the criteria for when companies can recognize and record sales as revenue. According to these guidelines, companies can only recognize revenue when certain milestones have been met or agreed upon. These milestones are usually related to the completion of contractual obligations, delivery of goods and services, and transfer of ownership. They also specify when and how often a company is allowed to estimate and report revenue, and in what order different types of revenue can be recognized. By adhering to GAAP Revenue Recognition Guidelines companies are able to accurately report their financial performance and maintain investor confidence.