Who Audits Public Companies- 2020 Edition

Straying from past trends, the number of SEC registrants has increased since last year, climbing from 5,973 in 2019 to 5,985 in 2020 – a 0.20% increase.

As mentioned by Accounting Today, the top ten firms by registrant count (EY, Deloitte, PwC, KPMG, BDO, Grant Thornton, Marcum, RSM, BF Borgers, and Crowe) increased their combined market share since last year. Together, these ten firms audit 65.7%, or two-thirds, of the 5,985 public registrants, up from 63.8% in 2018.

However, similar to last year, we are seeing changes to how registrants are identifying their filing status following recent SEC reporting amendments.

With an intent “to promote capital formation and reduce compliance costs for smaller companies while maintaining appropriate investor protections,” the SEC has expanded the scope of Smaller Reporting Companies, allowing companies to identify as a Smaller Reporting Company, or both a Smaller Reporting Company and either an Accelerated or Non-Accelerated Filer.

Oddly enough, there were even some Large Accelerated Filers that also identified as both a Large Accelerated Filer and a Smaller Reporting Company; it is rare, but it happens.1

These new amendments increase the number of eligible Smaller Reporting Companies without changing the “Accelerated Filer” threshold, which requires an auditor’s attestation of management’s assessment of internal control over financial reporting.

The methodology used for this analysis gives Large Accelerated and Accelerated Filer statuses precedent for companies that select both Large Accelerated or Accelerated Filer and Smaller Reporting company, as these companies “remain subject to the requirements that apply to accelerated filers.”

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Large Accelerated Filers

With 581 public company audits, EY audits 29% of Large Accelerated Filers. The vast majority of Large Accelerated Filers – almost 90% – are audited by the Big Four. There are 27 other firms that compete for the remaining 4.6% of this market.

Accelerated Filers

The Big Four, together with BDO and Grant Thornton, audit the greatest number of Accelerated Filers, accounting for over 62%. The remaining 487 companies were audited by 41 other firms.

Non-Accelerated Filers

The Big Four audit almost two-thirds of Non-Accelerated filers. Marcum, immediately following the top four firms, accounts for 3.2% of this market. The remaining 32% of Non-Accelerated filers are audited by 66 other firms.

Smaller Reporting Companies

Perhaps unsurprisingly, the audit firm market has a very different landscape depending on whether you are surveying large or small public companies. When it comes to larger public companies, the Big Four dominate the market. However, when looking at smaller reporting companies, the top firms are BF Borgers, M&K CPAs, Prager Metis, BDO, Marcum, RBSM and Boyle CPA.

Together, these seven auditors account for just 23.1% of this market; 210 firms account for the remaining 76.9% – highlighting the level of competition among these companies.

Non-Accelerated Filers and Smaller Reporting Companies

We see very similar instances in the Non-Accelerated Filers & Smaller Reporting Companies market, with the top firms being Marcum, MaloneBailey, EY, BDO, BF Borgers, and Deloitte. Combined, these six firms audit 33.6% of this market; leaving the remaining 66.4% to 155 other firms.


Please stay tuned for our follow-up analyses, where we’ll take a much closer look at the audit firms competing for non-accelerated filers and/or smaller reporting companies, as well as those companies having dual-filer statuses.


For more information on this analysis, please contact us.

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1.In 2019, two SEC registrants filed as Large Accelerated Filer + Smaller Reporting Company: Dicerna Pharmaceuticals Inc. [Nasdaq: DRNA], audited by Deloitte, and Myovant Sciences Ltd. [NYSE: MYOV], audited by EY.