Auditor Concentration: A Replication and Extension for the UK Audit Market 1991–1995

This paper examines the issue of auditor concentration in the UK during the period from 1991 to 1995. It shows that in 1995 the Big Six held 75% of the total number of audits and collectively earned 92% of the total audit fees. There was only a small increase in auditor concentration during the five year period, resulting from companies switching from small audit firms to Big Six and newly listed companies choosing a Big Six firm. The paper also examines auditor concentration within industries. Finally, the study assesses the measurement methods most commonly used in auditor concentration studies. Copyright Blackwell Publishers Ltd 1999.