Deloitte vs EY: full comparison for 2026
Quick verdict
Deloitte (4.3/5) edges ahead of EY (4.2/5) overall. Deloitte is the better choice for large regulated groups needing documented AI controls. EY is the stronger option for enterprises building AI risk into existing controls. The right choice depends on how independent you need the advice to be, your regulatory exposure, and your budget.
Deloitte vs EY: head-to-head summary
| Criterion | Deloitte | EY |
|---|---|---|
| Founded | 1845 | 1989 |
| HQ | London, UK | London, UK |
| Team size | 460,000+ | ~400,000 |
| Rating | 4.3 / 5 | 4.2 / 5 |
| Primary differentiator | Regulatory and audit teams beside the AI advisers, with global reach | AI risk work folded into existing technology risk and controls programs |
| Pricing model | Program fees; rates not published | Engagement fees per scope; rates not published |
| Min. engagement | Not disclosed | Not disclosed |
| Primary tech stack | EU AI Act, NIST AI RMF, GDPR | EU AI Act, NIST AI RMF, GDPR |
| Industries served | Banking, Insurance, Healthcare, Government & public sector, Energy | Financial services, Insurance, Public sector, Energy, Consumer |
Deloitte vs EY: overview
Deloitte
With more than 460,000 people and roots in an 1845 London accounting practice, Deloitte has the widest reach of any firm on this list. Its AI advisory sits next to risk and regulatory teams, which helps banks, insurers, and health systems that must document how each model is governed. Deliverables tend to be thorough and heavy. Expect large teams, long timelines, and a natural path into Deloitte's own implementation work.
EY
EY was formed by the 1989 merger of Ernst & Whinney and Arthur Young and employs about 400,000 people. Its advisory teams cover responsible AI, AI risk, and compliance programs, and its technology risk leaders have spoken publicly about how far real AI assurance still has to go. That candor is useful for buyers who want an honest view of what can be certified today. Like the rest of the Big Four, it sells implementation as well.
Services and capabilities: Deloitte vs EY
| Capability | Deloitte | EY |
|---|---|---|
| Readiness assessment | ✓ | ✓ |
| Use-case prioritization | ✗ | ✗ |
| TCO / ROI modeling | ✗ | ✗ |
| AI governance & EU AI Act | ✓ | ✓ |
| Build vs. buy advice | ✗ | ✗ |
| Independent audit or assurance | ✓ | ✓ |
| Roadmap any vendor can implement | ✗ | ✗ |
| Delivery capability after advice | ✓ | ✓ |
Frameworks and platforms: Deloitte vs EY
| Framework / platform | Deloitte | EY |
|---|---|---|
| EU AI Act | ✓ | ✓ |
| GDPR | ✓ | ✓ |
| DORA | ✓ | N/A |
| NIST AI RMF | ✓ | ✓ |
| ISO/IEC 42001 | N/A | N/A |
| Azure | ✓ | ✓ |
| AWS | N/A | N/A |
| Google Cloud | N/A | N/A |
Pricing comparison: Deloitte vs EY
| Criterion | Deloitte | EY |
|---|---|---|
| Minimum engagement | Not disclosed | Not disclosed |
| Engagement models | Fixed-scope assessment, Multi-use-case advisory, Audit or certification, Delivery team | Fixed-scope assessment, Multi-use-case advisory, Audit or certification, Delivery team |
| Rate transparency | Not public | Not public |
| Price tier | Mid-market | Mid-market |
Target audience comparison: Deloitte vs EY
| Dimension | Deloitte | EY |
|---|---|---|
| Best company size | Enterprise | Enterprise |
| Best industries | Banking, Insurance, Healthcare | Financial services, Insurance, Public sector |
| Best use cases | Model governance documentation for a bank or insurer., Group-wide AI policy across many countries. | Adding AI risk to an existing controls framework., Responsible AI policies for a large insurer. |
| Typical project type | Fixed-scope assessment | Fixed-scope assessment |
Deloitte vs EY: pros and cons
| Deloitte | |
|---|---|
| + | Widest geographic reach on this list |
| + | Change and workforce programs are mature |
| + | Regulators know its methods |
| - | Slow and expensive for a mid-size company's first assessment |
| - | Advice often leads into Deloitte's own delivery work |
| - | Audit-client independence rules apply |
| EY | |
|---|---|
| + | Ties AI risk to controls frameworks finance teams already use |
| + | Realistic public view on the limits of AI assurance |
| + | Large global bench |
| - | Premium fees |
| - | Sells delivery alongside advice |
| - | Audit-client independence rules apply |
Who should choose Deloitte?
A typical fit: model governance documentation for a bank or insurer.
Regulatory and audit teams beside the AI advisers, with global reach. Minimum engagement is not publicly disclosed. Works best with clients in Banking, Insurance, Healthcare, Government & public sector, Energy.
Who should choose EY?
A typical fit: adding AI risk to an existing controls framework.
AI risk work folded into existing technology risk and controls programs. Minimum engagement is not publicly disclosed. Works best with clients in Financial services, Insurance, Public sector, Energy, Consumer.
Decision matrix: Deloitte vs EY
| Your situation | Recommended choice |
|---|---|
| You want advice with no build contract attached | Neither; write the build as a separate decision |
| Finance needs run costs before approving anything | Neither lists cost modeling; ask for a sample |
| Some of your use cases may be high-risk under the EU AI Act | Both cover AI Act classification |
| You need an outside check on a system already built | Both offer audit or assurance |
| You want the same firm to build what it recommends | Both can deliver |
| Your budget is at the lower end | Compare: Deloitte (Not disclosed) vs EY (Not disclosed) |
| You need advisers in many countries at once | Deloitte |
Use case fit: Deloitte vs EY
| Use case | Deloitte fit | EY fit | Winner |
|---|---|---|---|
| Model governance documentation for a bank or insurer. | Strong | Limited | Deloitte |
| Group-wide AI policy across many countries. | Strong | Limited | Deloitte |
| Adding AI risk to an existing controls framework. | Limited | Strong | EY |
| Responsible AI policies for a large insurer. | Limited | Strong | EY |
Verdict: Deloitte vs EY
Deloitte (4.3/5) is the stronger overall choice for most AI Advisory projects. Regulatory and audit teams beside the AI advisers, with global reach.
EY (4.2/5) is worth a look if you need responsible AI policies for a large insurer. If your situation matches that, EY is a competitive option.
Related comparisons
Deloitte vs EY FAQ
Is Deloitte better than EY?
Deloitte (4.3/5) scores higher overall, but "better" depends on your use case. Deloitte's strongest advantage: widest geographic reach on this list. EY's strongest advantage: ties AI risk to controls frameworks finance teams already use.
How do Deloitte and EY differ in pricing?
Deloitte's pricing: program fees; rates not published. EY's pricing: engagement fees per scope; rates not published. Any hourly bands shown come from Clutch, not a published rate card, so a scoping call is still needed for a project quote.
Which is better for enterprise: Deloitte or EY?
Deloitte is the larger team and typically the better enterprise-scale choice. For very large programmes, verify team size and compliance coverage directly with each firm before shortlisting.
What are the main differences between Deloitte and EY?
Deloitte's primary differentiator is: regulatory and audit teams beside the AI advisers, with global reach. EY's primary differentiator is: AI risk work folded into existing technology risk and controls programs. They also differ in team size (460,000+ vs ~400,000), minimum engagement (Not disclosed vs Not disclosed), and primary industries served (Banking, Insurance vs Financial services, Insurance).
Verify all details directly with each firm before making a decision.