Since 2009, Deloitte increased its revenue year-on-year to 46.2 billion U.S. dollars in 2019. Deloitte was also the largest of the Big Four accounting firms worldwide that year. The success of Deloitte can in part be attributed to its dominance in the Americas. Compared to the other Big Four firms, Deloitte generated over 6.4 billion U.S. dollars more in revenue in the region than the second largest of the Big Four, PwC, in 2019, and twice as much as KPMG. Deloitte’s high revenue streams on the American continent are reflected in the United States as Deloitte was the largest accounting firm in the country.
Deloitte offers four main services - audit and enterprise risk services, consulting, tax and financial advisory. In 2019, the largest share of these service lines was consulting, overthrowing the audit and risk advisory service line, which consistently generated the highest annual revenue up until 2016. The consulting service line is also the fastest growing segment. The revenue generated by this service has increased from 4.5 billion U.S. dollars to around 18.7 billion U.S. dollars between 2006 and 2019.