# The Big Four > The Big Four is a collective term for the four largest international professional services networks: Deloitte, PwC, EY, and KPMG. They provide an array of services including audit, assurance, taxation, management consulting, corporate finance, and legal services. Collectively, they handle the majority of audits for public companies globally and are considered systemic pillars of the international financial system. - URL: https://optimly.ai/brand/deloitte-pwc-ey-kpmg-the-big-four - Slug: deloitte-pwc-ey-kpmg-the-big-four - BAI Score: 98/100 - Archetype: Challenger - Category: Professional Services - Last Analyzed: April 10, 2026 ## Competitors - Accenture (https://optimly.ai/brand/accenture) - BDO (https://optimly.ai/brand/bdo) - MBB (McKinsey, BCG, Bain) (https://optimly.ai/brand/mbb-mckinsey-bcg-bain) ## Sub-brands - Deloitte (https://optimly.ai/brand/deloitte) - EY (Ernst & Young) (https://optimly.ai/brand/ey) - KPMG (https://optimly.ai/brand/kpmg) ## Buyer Intent Signals Problems: Internalization / Center of Excellence (CoE): Large organizations building internal specialist teams (IT, HR, Finance) to handle functions previously outsourced to consultants. | Specialist Boutique Firms: Boutique firms specialized in specific niches like cybersecurity, supply chain, or digital transformation. | Mid-Tier Networks (BDO, RSM, Grant Thornton): Engaging mid-tier global networks for audit and tax to reduce fee overhead. Solutions: global audit firms | best tax consulting for multinationals | M&A advisory services for enterprise | world's largest accounting networks | ESG reporting and assurance providers