EY

EY, previously known as Ernst & Young, is a multinational professional services network that provides assurance, tax, information technology services, consulting, and transactions advice. It is one of the Big Four professional services firms, along with Deloitte, KPMG and PwC. Its principal service lines include Assurance, Consulting, Strategy and Transactions, and Tax. Its strategy and transactions services are provided under the EY-Parthenon brand.

The EY network is composed of member firms of Ernst & Young Global Limited, a UK company limited by guarantee headquartered in London, England. The member firms are structured as separate legal entities. As of 2026, it employs approximately 406,000 people across more than 700 offices in over 150 countries and territories. Janet Truncale succeeded Carmine Di Sibio as global chair and chief executive in July 2024.

The firm was formally created as Ernst & Young through a merger in 1989, though its oldest predecessor firms were founded in 1849. In 1989, Ernst & Whinney merged with Arthur Young & Co. to create Ernst & Young. In 2013, the organization changed its brand name to EY.