Ernst & Young (EY) is a multinational professional services firm headquartered in London, United Kingdom with over 167,000 employees working in more than 700 offices across over 140 countries. EY provides assurance, tax, consulting and advisory services to companies. The firm is led by Chairman and CEO Mark Weinberger and Global COO John Ferraro and generated $24.4 billion in revenue in 2012 with a workforce of 167,000 people.