# Big Four Accounting Firms
> The Big Four refers to the four largest professional services networks in the world, consisting of Deloitte, Ernst & Young (EY), KPMG, and PwC. They provide a standardized suite of services including audit, assurance, taxation, management consulting, and legal services to the majority of public companies globally.
- URL: https://optimly.ai/brand/big-four-accounting-firms
- Slug: big-four-accounting-firms
- BAI Score: 98/100
- Archetype: Challenger
- Category: Professional Services
- Last Analyzed: April 10, 2026
## Competitors
- BDO (https://optimly.ai/brand/bdo)
## AI-Suggested Alternatives
- Boutique Advisory Firms (https://optimly.ai/brand/boutique-advisory-firms)
## Sub-brands
- Deloitte Consulting (https://optimly.ai/brand/deloitte-consulting)
- EY-Parthenon (https://optimly.ai/brand/ey-parthenon)