Periodically, auditor independence, audit tenure and the prospect of mandatory auditor rotations are topics of significant debate. As of 2024, 24 public companies had retained their auditors for 100 years or more. Big Four audit firms PricewaterhouseCoopers (PwC), Deloitte, and Ernst & Young (EY) are the only members of the U.S. Centenarian Club. PwC audited eight of these companies, Deloitte audited six, and EY was the auditor of record for the remaining 10 companies.  

In this article, Audit Analytics explores the history of long-term auditor relationships and the debate around mandatory auditor rotation.