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.

PwC provides audit and assurance, consulting, and tax services across industries. It offers services including financial statement audits, enterprise risk and controls solutions, technology strategy, and managed services, serving sectors such as financial services, healthcare, technology, and consumer markets. It was founded in 1998 and is based in London, United Kingdom.

EY operates as a professional services firm providing services across assurance, tax, transaction, and advisory. The company offers audit and assurance, tax planning and compliance, corporate finance consulting, management consulting, risk management, legal services, technology consulting, and sustainability consulting. EY serves clients in various sectors, including financial services, healthcare, technology, and government. EY was formerly known as Ernst & Young. It was founded in 1989 and is based in London, United Kingdom.

KPMG is a global network of professional firms specializing in Audit, Tax, and Advisory services across various sectors. The company offers a broad range of services including financial auditing, tax planning and compliance, business advisory, and consulting on sustainability, risk management, and regulatory issues. KPMG primarily serves industries such as healthcare, financial services, government, and public sector organizations. It was founded in 1987 and is based in Amstelveen, Netherlands.

The Boston Consulting Group is a global management consulting firm focused on business strategy and organizational growth. The company offers management consulting, technology and design, and corporate and digital ventures. BCG serves business leaders and organizations addressing challenges and opportunities. It was founded in 1963 and is based in Boston, Massachusetts.

McKinsey & Company operates as a global management consulting firm. It focuses on advising businesses, governments, and institutions. The company offers services in strategy, technology innovation, leadership development, and capability building without specifying particular products. McKinsey primarily serves the private, public, and social sectors with a broad range of consulting services. It was founded in 1926 and is based in New York, New York.