Ernst & Young (EY) is one of the "Big Four" audit firms and the third largest professional services firm worldwide. It operates as a network of member firms in over 700 offices across 150 countries. EY provides assurance, tax, consulting, and advisory services to companies. The firm was formed through a merger in 1989 and rebranded as EY in 2013. Key services include assurance, tax, advisory, and transactions. EY's vision is to build a better working world through the use of technology and by positioning itself for future success and opportunities. Integrity, respect, teamwork, energy, and courage define EY's core values.