Raphael Bohne
Research expert covering professional services
"Big Four" accounting/audit firms - statistics & facts
The term Big Four, in relation to auditing and accounting, refers to the four major professional services networks specializing in accountancy and professional services. These firms are Deloitte, PricewaterhouseCoopers (PwC), Ernst & Young (EY), and KPMG. The Big Four firms serve as auditors to the majority of publicly traded companies and also deal with a number of private companies. In recent years, they have branched out into the outsourcing of public services in some countries, including consultation on government responses to the COVID-19 pandemic. The combined revenue of the Big Four was almost 204 billion U.S. dollars in 2023.
Ever-increasing revenues
According to revenue figures from 2023, Deloitte was the biggest of the four companies, with almost 65 billion U.S. dollars generated in revenue. PwC generated approximately 53 billion U.S. dollars in revenue in the same year. EY and KPMG, the remaining two of the Big Four, also saw their revenue streams increase significantly. When broken down by function, PwC and EY generated the largest share of their revenue through their audit/assurance branches, while Deloitte and KPMG generated the largest share of their revenue through their advisory/consulting branches.Employee numbers greater than many military forces
Each of these four firms increased their number of employees in 2023. Deloitte had the most employees at approximately 457,000 whereas KMPG had the fewest with a workforce of roughly 300,000. In total, the Big Four employed more than 1.5 million people in 2023. Comparatively, the United States, with one of the largest armies in the world, had 1.39 million active military personnel in 2022.
