Revenue of the Big Four accounting / audit firms worldwide by function 2021

In 2021, Pricewaterhouse Coopers, also known as PwC, generated some 17.1 billion U.S. dollars in revenue from its assurance segment, making it the leader in the assurance market among the Big Four.

The Big Four worldwide

The Big Four consist of Pricewaterhouse Coopers (PwC), Deloitte, Ernst & Young (EY), and KPMG. These companies are the four largest accounting and audit firms worldwide. In 2020, they brought in nearly 160 billion U.S. dollars in revenue combined. Out of the four, Deloitte had the greatest number of employees. Second in the list was Ernst & Young, followed by PwC, and KPMG. Most of Deloitte’s total revenue came from the Americas region, bringing in over 25 billion U.S. dollars in 2020. Both PwC’s and Ernst & Young’s America’s region also collected the highest amount of revenue for them.

The Big Four in the U.S.

These four companies have the most influence in the accounting and audit sector in the United States, auditing over 80 percent of U.S. public companies. Out of the Big Four, Deloitte brought in the highest gross revenue in the United States. Following Deloitte was PwC, bringing in 15.62 billion U.S. dollars, then Ernst & Young, which brought in 13 billion U.S. dollars. KPMG brought in the least, generating just under nine billion U.S. dollars in that year.