Written by:
E
Editorial Team
DSG.AI
A maintained, sourced reference for what each internal audit sourcing model actually costs in 2026. Every figure below links to its source and is dated. The table is the reference; the methodology and sources follow it.
Last updated: 2026-06-15. Refresh cadence: annual (or when a primary fee/salary source publishes new data).
Internal audit sourcing cost at a glance (2026, US)
| Sourcing model | Headline cost | How it is billed | Effective $/hr* | What you actually get |
|---|---|---|---|---|
| In-house: staff auditor | $68,750–$99,750 salary | Fixed annual (loaded ≈ 1.4× salary) | ~$65–$95 | Year-round capacity; sample-based testing limited by team size |
| In-house: senior auditor | $89,750–$121,750 salary | Fixed annual (loaded ≈ 1.4× salary) | ~$85–$116 | Experienced reviewer; still fixed capacity you pay for in slow quarters |
| Mid-tier / regional firm | $200–$400/hr | Hourly or fixed-fee engagement | $200–$400 | Below Big 4 rates; capped by purchased hours |
| Big 4 co-sourcing | $200–$550/hr (senior $300–$500) | Hourly or fixed-fee engagement | $200–$550 | Brand + breadth; you often pay senior rates for junior-performed work |
| Audit-as-a-Service (AaaS) | Subscription, scoped to the audit plan | Recurring subscription | ~$120–$180 equivalent | Audits performed (not staffed); full-population testing, 40–60% below Big 4 co-sourcing rates |
*Effective $/hr is illustrative, derived in the Methodology note below. In-house figures look low per hour but exclude the cost of idle capacity: a function staffed for peak season is paid year-round.
Sources for the table
- In-house salaries: Robert Half 2026 Salary Guide, senior internal auditor and internal auditor (accessed 2026-06-15).
- Loaded-cost multiple: U.S. Bureau of Labor Statistics, Employer Costs for Employee Compensation, March 2025: wages and salaries were 70.3% of total employer cost in private industry, so fully loaded cost ≈ salary ÷ 0.70 ≈ 1.4×.
- Firm billing ranges (mid-tier and Big 4): published accounting/consulting fee data, Embark (accessed 2026-06-15): consulting fees $200–$550/hr, senior-level $300–$500/hr; offshore-staffed engagements can run $90–$160/hr at a reduced service level.
- AaaS economics: DSG.AI first-party data across 250+ production AI deployments: 40–60% below Big 4 co-sourcing rates, 50%+ reduction in audit cycle time, 3–5x increase in audit coverage.
How sourcing splits by organization size
Co-sourcing and outsourcing are now the norm, and the largest functions use them most, not least.
| Metric | Figure | Source |
|---|---|---|
| Internal audit functions using outsourcing/co-sourcing | ~60% | IIA 2024 North American Pulse of Internal Audit |
| Share of work sourced: smallest functions | ~32% | IIA 2024 North American Pulse |
| Share of work sourced: largest functions | ~74% | IIA 2024 North American Pulse |
| CAEs reporting outsourcing/co-sourcing (global) | 54% | IIA 2022 global research |
| Most commonly sourced areas | cybersecurity, IT, regulatory compliance | IIA 2024 North American Pulse |
What an in-house auditor really costs
Salary is the smallest line. Using the BLS loaded-cost multiple on the Robert Half midpoints:
| Role | Salary midpoint | Fully loaded (≈ ÷ 0.70) | Plus |
|---|---|---|---|
| Staff auditor | ~$84,250 | ~$120,000 | recruiting, tooling, training, external quality reviews |
| Senior auditor | ~$105,750 | ~$151,000 | recruiting, tooling, training, external quality reviews |
A minimum credible two-person function therefore runs roughly $250,000–$280,000 per year before software and recruiting, and delivers a fixed number of sample-based audits.
Methodology
- Scope. US national figures, 2026. Salaries are base salary; firm figures are client billing rates, not salaries. Adjust for region; the relative gaps hold.
- Loaded cost. Fully loaded employer cost is estimated as salary ÷ 0.70, from the BLS finding that wages and salaries are ~70% of total employer compensation cost (benefits ~30%). This excludes recruiting fees, audit-management tooling, training, and the external quality assessments the IIA Standards require.
- Effective $/hr (in-house). Loaded annual cost ÷
1,500 productive audit hours per auditor per year (a planning assumption after admin, training, and leave, not a billed rate). At the senior midpoint ($151,000 ÷ 1,500 ≈ $101/hr). - Effective $/hr (AaaS). Illustrative: 40–60% below a representative $300/hr Big 4 co-sourcing blended rate gives ~$120–$180/hr equivalent. AaaS is sold as a subscription scoped to the audit plan, not by the hour; the per-hour figure is for comparison only.
- What is excluded. Idle-capacity cost of in-house teams (you pay full-time for seasonal demand), coverage differences (full-population testing vs sampling), and one-off setup or system-access costs. These shift the real comparison further toward variable models for lumpy audit plans.
Sources
- Robert Half, 2026 Salary Guide: Senior Internal Auditor and Internal Auditor. Accessed 2026-06-15.
- U.S. Bureau of Labor Statistics: Employer Costs for Employee Compensation, March 2025.
- Embark: What Are the Fees & Hourly Rates of Accounting Consulting Firms? Accessed 2026-06-15.
- The Institute of Internal Auditors: 2024 North American Pulse of Internal Audit.
- The Institute of Internal Auditors: 2022 global research report.
- Richard Chambers (former IIA president): The true cost of an internal audit is often a well-kept secret.
DSG.AI maintains this page as a reference. Figures are sourced as of the dates shown and refreshed annually. AaaS performance figures are first-party, measured across 250+ production AI deployments; independent cost figures link to their primary sources above.
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