EY is a multinational professional services organisation and is headquartered in London, England. EY is a professional service company and considered one of the Big Four Auditors, along with Deloitte, KPMG, and PriceWaterhouse Coopers (PwC). The organisation operates as a network of member firms which are separate legal entities in individual countries. It has 231,000 employees in over 700 offices around 150 countries in the world. It provides assurance, (including financial audit), tax, consulting and advisory services to companies worldwide.