quality:correction, stylistic:style_transfer, structural:reformatting, linguistic:paraphrasing, information:highlighting
Firms

Depending on its size, a company may be legally required to have their financial statements audited by a qualified auditor, and audits are usually carried out by accounting firms.

Accounting firms grew in the United States and Europe in the late nineteenth and early twentieth century, and through several mergers there were large international accounting firms by the mid-twentieth century. Further large mergers in the late twentieth century led to the dominance of the auditing market by the "Big Five" accounting firms: Arthur Andersen, Deloitte, Ernst & Young, KPMG and PricewaterhouseCoopers. The demise of Arthur Andersen following the Enron scandal reduced the Big Five to the Big Four.