Grant Thornton

1. 01Typical price range for tax advisory support for corporations0/4
2. 02How does an external audit differ from an internal audit for corporations?0/4
3. 03Top business advisory solutions for expanding mid-size companies1/4
4. 04What are some other ways companies can ensure regulatory compliance besides standard assurance services?0/4
5. 05What are the best audit and assurance services for large organizations in the US?4/4
6. 06Common challenges companies face during annual assurance reviews0/4
7. 07What affects the cost of audit and assurance services for large US businesses?0/4
8. 08When should a business seek specialized advisory support for mergers and acquisitions?0/4
9. 09Alternatives to traditional yearly audits for large organizations0/4
10. 10Is it better to hire one firm for both audit and advisory needs or use separate specialists?0/4
11. 11Tax consulting vs. business advisory services—what’s the main difference for midsize businesses?0/4
12. 12Who needs tailored compliance risk assessment services?0/4
13. 13Are comprehensive tax advisory packages worth it for growing enterprises?0/4
14. 14Best solutions for integrating AI into financial advisory for efficiency gains?0/4
15. 15How to handle discrepancies found in a financial statement audit?0/4

Columns, left to right: OpenAI, Claude, Perplexity, Gemini. Across the study, on 50% of the questions where a company is named, only one AI assistant names it.

“What are the best audit and assurance services for large organizations in the US?”

For large US organizations, the strongest audit and assurance options are typically the Big Four—Deloitte, PwC, EY, and KPMG—plus large alternatives such as Grant Thornton, BDO, and RSM. The best choice depends on public-company reporting needs, industry expertise, global coverage, technology risk, and independence requirements.

Best services by need

Need · Best-fit services · Strong providers

Public-company financial statement audits · PCAOB-registered independent audit, SOX 404 internal-control attestation, quarterly review support · Deloitte, PwC, EY, KPMG

G …

The AI’s answer as we received it, shortened and not checked for accuracy.

See how every company did, and how this was measured.

These 14 checks ran during the audit and are what the AI readiness part of the overall score counts. The scan above ran later and is stricter on Link headers and Markdown, so a check can pass here and not there.

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<a href="https://aeo-audit.rezolve.com/us/finance/grantthornton.com"><img src="https://aeo-audit.rezolve.com/finance/badges/grantthornton.com.svg" alt="Overall score 41 of 100, Finance AI Visibility Study 2026" width="280" height="64"></a>