EY operates as an organization, providing assurance, consulting, tax, strategy, and transactions services. The company offers services such as strategic consulting, financial advisory, audit and assurance, technology transformation, and sustainability consulting. EY serves clients across industries, including financial services, healthcare, technology, and government, aiming to address their specific challenges. EY was formerly known as Ernst & Young. It was founded in 1989 and is based in London, United Kingdom.

Deloitte provides professional services, focusing on audit, consulting, tax, and advisory services across various sectors. The company offers services including management consulting, financial advisory, risk management, and technology consulting to help clients with business challenges. Deloitte serves clients across industries such as consumer, financial services, government, life sciences, and technology. It was founded in 1845 and is based in London, United Kingdom.

KPMG US operates as a multidisciplinary company operating in the professional services industry. The company offers a range of services including advisory, audit, and tax services, with a focus on helping clients meet challenges and respond to opportunities through deep industry knowledge and practical approaches. KPMG US primarily serves sectors such as banking and capital markets, consumer goods and retail, energy and chemicals, healthcare and life sciences, and technology, media and telecom. It is based in New York, New York.

PwC provides audit and assurance, consulting, and tax services across various industries. The company includes services such as financial statement audits, risk modeling, sustainability and ESG consulting, digital assurance, enterprise strategy, and managed services. PwC serves sectors including consumer markets, financial services, health industries, industrial products and services, and technology, media, and telecommunications. It was founded in 1998 and is based in London, United Kingdom.

Grant Thornton operates as an independent firm specializing in audit and assurance, tax, and advisory services across various sectors. The company offers services including financial statement audits, tax planning and compliance, business consulting, risk management, and transaction advisory. Grant Thornton serves public and private organizations in sectors such as healthcare, not-for-profit, manufacturing, and technology. Grant Thornton was formerly known as Alexander Grant & Co.. It was founded in 1924 and is based in Chicago, Illinois.

Boston Consulting Group specializes in business strategy and management consulting across various sectors. The company offers services including management consulting, technology and design, and corporate and digital ventures, focused on creating competitive advantages and societal benefits. It serves businesses and societal leaders addressing various challenges and opportunities. It was founded in 1963 and is based in Boston, Massachusetts.