Audit fee increases accelerated again in fiscal year 2024, with U.S. public-company audit bills rising roughly 8% on average and the typical engagement now costing more than $2.7 million; for large accelerated filers, the average tops $6 million. The reasons are structural, not cyclical. A shrinking accountant pipeline, an expanding regulatory footprint, more complex clients, a concentrated market of qualified firms, and rising liability costs all push in the same direction. Each pressure amplifies the others, and none of them are easing in the near term.
Why Audit Labor Costs Keep Climbing
Labor is the majority of any audit fee, so the accountant shortage translates directly into invoices. More than 300,000 professionals left the field between 2019 and 2022. Accounting graduates dropped to about 47,000 in the most recent AICPA reporting period, down 10% from 2021. New CPA exam applicants fell from 48,004 in 2016 to 28,082 in the 2023–2024 cycle, while the Bureau of Labor Statistics projects about 136,400 accounting openings per year.
The 150-credit-hour licensure requirement pushes students toward finance and tech roles that pay more without demanding a fifth year of college. Partner retirements are accelerating. Some states have started relaxing the 150-hour rule and 2024 saw a 12% uptick in accounting program enrollment, but bachelor’s completions are still declining, so relief is years away.
Firms respond by paying more. Starting salaries have jumped, retention bonuses are standard, and specialists in cybersecurity, forensic accounting, and complex valuations command rates well above general audit staff. Those are exactly the skills the PCAOB is pressing firms to deploy, so the market for them is tight and getting tighter.
Regulatory Scope Keeps Expanding
Every new inspection priority or standard adds hours. The PCAOB’s 2025 inspection priorities target financial services firms exposed to commercial real estate and interest-rate volatility, technology companies dealing with AI-related inventory valuation, and any company with recent merger or acquisition activity. The board is also pressing auditors on going-concern assessments, critical audit matters, and the use of technology in audit procedures.1Public Company Accounting Oversight Board. Spotlight Staff Priorities for Inspections and Interactions With Audit Committees
When the PCAOB flags an area, auditors respond with more documentation and testing. Recent amendments to AS 1201 and AS 2101 changed how firms supervise multi-location audits, and AS 2310 changed the rules on confirmations. Each new standard forces firms to retrain staff, update methodologies, and perform procedures that didn’t exist before.
The SEC layers on its own requirements. Interpretive guidance on internal control over financial reporting has driven more rigorous identification and classification of deficiencies.2U.S. Securities and Exchange Commission. Definition of the Term Significant Deficiency The SEC’s final climate disclosure rule will require large accelerated filers to obtain limited assurance over Scope 1 and Scope 2 greenhouse gas emissions for fiscal years beginning in 2026, with accelerated filers following in 2028 and reasonable assurance phasing in for large filers by 2033.3U.S. Securities and Exchange Commission. The Enhancement and Standardization of Climate-Related Disclosures Commenters on that rule warned the attestation requirement would substantially raise audit fees, and companies inside the 2026 window are already budgeting for it.
FASB Standards
Standards from the Financial Accounting Standards Board add cost in waves. ASC 842 brought operating leases onto the balance sheet, forcing auditors to test the completeness of lease inventories, validate discount rates, and evaluate practical expedients.4The CPA Journal. A Discussion of Practical Expedients in ASC Topic 842 ASC 606 produced a similar surge for revenue recognition. First-year implementation effort fades, but ongoing testing of complex standards is a permanent addition to scope.
Crossing the SOX 404(b) Threshold
Companies that move from exempt to nonexempt under Sarbanes-Oxley 404(b), generally those with $75 million or more in publicly held shares that don’t qualify as emerging growth companies, face a steep one-time jump. A GAO analysis found a median increase of $219,000, or 13%, in the year a company becomes nonexempt. Overall, nonexempt companies pay about 19% more than exempt peers because of the additional planning, internal control testing, and quality review the integrated audit demands.5U.S. Government Accountability Office. Sarbanes-Oxley Act – Compliance Costs Are Higher for Larger Companies
How Client Complexity Drives the Bill
The audit fee is a function of hours, and complex clients need more hours. Companies growing through acquisitions add layers around consolidation, purchase price allocation, and goodwill impairment testing. Each deal brings new accounting policies, unfamiliar IT systems, and additional personnel to evaluate. The PCAOB specifically flags recent M&A activity as an inspection selection factor, which gives firms every incentive to staff those engagements heavily.
Multinational operations multiply the work again. Component auditors in each jurisdiction have their own statutory frameworks that sit alongside U.S. GAAP, and the SEC requires the reconciliation between local standards and U.S. GAAP to be audited and opined on separately.6U.S. Securities and Exchange Commission. Division of Corporation Finance – International Financial Reporting and Disclosure Issues Recent PCAOB standards on dividing responsibility with other accounting firms add further supervision requirements for the lead auditor.
The IT environment often catches finance teams off guard. Multiple legacy systems, fragmented ERP platforms, or hybrid cloud setups force auditors to bring in IT specialists to test system-level controls, data migration accuracy, and access management. Those specialists bill at premium rates. Fair value measurements, derivatives, and impairment assessments pull in valuation experts on top of that.
A Concentrated Market With Little Pricing Pressure
The Big Four (Deloitte, EY, KPMG, and PwC) audit virtually all of the S&P 500. In fiscal year 2022, those four firms collected roughly 99.7% of the $5.3 billion in audit fees paid by S&P 500 companies, leaving Grant Thornton and BDO to split about $15 million. Concentration at that level limits the pricing pressure that real competition would create.
Switching auditors is expensive. Academic research suggests a successor auditor’s first-year fee runs about 15% higher than the outgoing firm’s, reflecting startup costs for learning the business, testing opening balances, and building institutional knowledge. That switching cost operates as a lock-in and weakens the client’s leverage after the initial engagement.
The number of registered audit firms has been shrinking, and mid-tier firms face the same talent constraints as the Big Four. Demand for qualified auditors keeps outrunning supply, and fee negotiations reflect that imbalance.
Risk and Liability Priced Into Every Engagement
Firms price risk into what they charge. Professional liability insurance premiums have climbed sharply, with the steepest increases in high-exposure sectors like financial services and technology. Claim frequency and severity against accounting firms have both trended up, and insurers have priced accordingly. Those premiums are overhead that gets recovered through billing rates.
The firm’s own risk assessment shapes the staffing mix. A client with a history of restatements, aggressive accounting positions, complex debt covenants, or elevated fraud risk gets more experienced seniors and partners on the engagement. That’s deliberate protection against litigation, and it’s significantly more expensive per hour than a team weighted toward junior staff. Partner review, technical consultation, and quality control add non-billable time that the firm recovers through the fee.
Technology investment is largely non-optional. AI-powered analytics, continuous monitoring platforms, and data extraction tools require capital upfront and specialists to operate. They may create efficiencies later, but in the near term they add to the cost base, and the PCAOB’s focus on how firms use technology makes manual-only approaches harder to defend.
What You Can Do About Rising Audit Fees
None of the structural drivers are under your control, but how your team runs the engagement is. The most effective lever is audit readiness. Every hour the audit team spends chasing a missing reconciliation, re-requesting a schedule, or waiting for management responses is an hour billed at full rate. Companies that deliver clean, complete workpapers on the promised timeline pay less than companies that don’t.
Competitive bidding helps, even if you keep your incumbent. Research shows incumbent auditors deliver higher-quality audits during bidding years and offer modest fee concessions to retain the work, and the quality improvement persists for years after reappointment. You don’t have to switch to benefit; you have to make the incumbent compete.
Get the audit committee into the fee conversation before the engagement letter arrives. Understanding the split between base audit hours, specialist costs, and risk premiums lets you target scope discussions where they’ll actually move the number. If IT complexity is the driver, investment in system integration or stronger internal controls can cut specialist hours. If a new standard is expanding scope, early communication about your implementation approach lets the audit team plan more efficiently.
Offshore delivery centers are part of the picture too. All Big Four firms run major service centers in India, and several are expanding in the Philippines to handle portions of the audit at lower labor cost. In practice, the savings don’t always flow through to the client, and pending legislation and tariff scenarios could compress the offshore cost advantage further.
Unpaid Audit Fees Can Threaten Independence
Rising fees carry a second risk: falling behind on payment can compromise the audit relationship itself. The SEC’s position is that prior-year audit fees should generally be paid before the current engagement begins, or the auditor’s independence may be called into question. The SEC will accept either a definite commitment to pay before the current audit report is issued, or a periodic payment arrangement with reasonable assurance the current fee will be settled before the next year’s audit begins.7Securities and Exchange Commission. Office of the Chief Accountant – Application of the Commission’s Rules on Auditor Independence
If unpaid fees become material relative to the expected current-year fee, the auditor can appear to hold a financial interest in the client’s results, and that is a direct threat to independence. For public companies, losing auditor independence means losing the ability to file audited financials with the SEC, which can trigger delisting and debt covenant violations. The AICPA’s ethics interpretation (ET §1.230.010) applies a similar framework to private-company audits. Budget for the increase, because the cost of not paying is far higher than the cost of paying.