Ernst & Young, commonly known as EY, is a global professional services firm headquartered in London, England. It is one of the "Big Four" accounting firms, providing services in areas such as audit, tax, consulting, and advisory. EY operates in more than 150 countries and employs hundreds of thousands of professionals worldwide. Founded in 1989 through a merger of Ernst & Whinney and Arthur Young & Co., EY has grown to become a leader in the industry. The firm is known for its commitment to building a better working world, focusing on innovation and sustainability in its services and operations.