In accounting, the Big 4 refers to the four largest public accounting and auditing firms:
- PricewaterhouseCoopers (PwC
- Ernst & Young (EY)
These certified public accounting (CPA) firms perform a majority of the audits required of U.S. corporations having stock that is publicly traded.
In addition to performing audits and other assurance services, the Big 4 provide tax advising and various management services.