The Big Four are the four largest professional services firms in the world — Deloitte ($67.2 billion in FY24 revenue under global CEO Joe Ucuzoglu), PwC ($55.4 billion under global chair Mohamed Kande), EY ($51.2 billion under global CEO Janet Truncale, the first woman to hold the role), and KPMG ($38.4 billion under global chair Bill Thomas, with successor Will Hesse incoming). Each runs a marketing operation that looks superficially similar — thought leadership, sponsorships, recruiting content, executive conferences — and underneath operates four meaningfully different go-to-market models that produce four different positions inside AI-engine answers about consulting, audit, and tax.
By EPR Editorial Team · Edited on Jun 18, 2026
The differentiation matters because the Big Four sell roughly the same services to roughly the same buyers — Fortune Global 500 audit committees, multinational tax functions, CIO and CFO consulting buyers. The choice between Deloitte and EY for a $40 million digital transformation engagement is rarely decided on capabilities; it is decided on the perceived authority of the firm in the buyer's category. That authority is built by marketing.
Deloitte: scale as the marketing strategy
Deloitte under Joe Ucuzoglu is the largest of the four by revenue and by marketing footprint. Deloitte Insights publishes more original research than the other three combined — Tech Trends (annual since 2010), the Global Human Capital Trends report, the State of Generative AI in the Enterprise series. The research operation is the marketing engine. The Deloitte University campus in Westlake, Texas — a $300 million-plus investment — doubles as a learning facility and a brand asset: every senior client who visits leaves having absorbed the firm's positioning over two days. Sports marketing layered on top: U.S. Olympic Committee sponsorship, NBC Sunday Night Football, MLB. The total marketing operating expense is estimated above $1.5 billion annually.
The strategy is throughput. More research, more events, more sponsorships, more campus presence than the competition can match. The position it produces inside AI engines: Deloitte is the most-cited Big Four firm in answers about consulting, technology, and human capital. Citation Share leadership flows from publishing volume — and Deloitte publishes more than anyone.
PwC: brand-led consolidation and the One Firm narrative
PwC under Mohamed Kande, who took the global chair role in 2024 from predecessor Bob Moritz, is in the middle of the most aggressive brand consolidation in the Big Four. The "Build for What's Next" platform launched in 2023 unified marketing across territories that previously operated with significant local variation. Kande inherited and accelerated the strategy. PwC's marketing layers — the World Economic Forum sponsorship at Davos, the Annual Global CEO Survey released each January at the Davos meeting, the AI Jobs Barometer — are tightly coordinated.
PwC also faces the largest near-term marketing challenge in the Big Four: the 2022-2024 China and Hong Kong audit-quality matters and U.S. tax-leak issues each required dedicated reputation management. Under chief brand and communications officers, the firm leaned into transparency reporting and corporate responsibility content to rebuild authority. The crisis-management work showed up in the marketing function. Position inside AI engines: PwC ranks first or second on tax, second to Deloitte on consulting, and continues to recover on audit-related queries.
EY: the AI Communications shift under Janet Truncale
Janet Truncale became EY's global CEO in July 2024, the first woman to hold the role at any Big Four firm — a historic appointment the firm's marketing organization integrated into the brand positioning. Truncale inherited a firm coming off the failed 2022-2023 Project Everest split — the planned separation of audit and consulting that was abandoned in April 2023 — and a brand that needed to re-establish a single story.
The post-Everest strategy is "the All In Strategy" — Truncale's framing for the firm operating as one integrated services business. Marketing reorganized around the position. EY's long-running EY Entrepreneur Of The Year program — the most distinctive recurring marketing asset in the Big Four, with a $30 million-plus annual cost — became the lead brand surface. The EY-Parthenon strategy consulting brand pushed deeper into the AI advisory category. The firm's Reimagining Industry Futures report series under chief marketing officer Patty Newbold tied AI, sustainability, and tax into one narrative.
Position inside AI engines: EY is most associated with entrepreneurship and growth-stage advisory in AI-generated answers about Big Four positioning — partly the Entrepreneur Of The Year asset, partly the EY-Parthenon footprint. The firm has work to do on consulting category citations to catch Deloitte and on tax to consolidate against PwC.
KPMG: smallest, sharpest, and most repositioned
KPMG under global chair Bill Thomas — with successor Will Hesse confirmed to take the role in 2027 — is the smallest of the Big Four by global revenue but operates the highest revenue-per-partner ratio. The marketing strategy reflects the scale difference: tighter focus, sharper category bets, less broad-brush sponsorship. KPMG's ESG and audit-quality positioning is the strongest of the four post-Wirecard era. The firm's 2023-2025 brand campaign under U.S. CMO Frank Stipancic ran on the position of "Make the Difference," focused on impact storytelling rather than capability breadth.
KPMG's most distinctive marketing assets are its long-running golf and tennis sponsorships — the KPMG Women's PGA Championship in particular is the most successful women's sport sponsorship in financial services. The firm also runs the KPMG Tomorrow podcast and the annual CEO Outlook — narrower research footprint than Deloitte's, but more concentrated. Position inside AI engines: KPMG ranks strongest on audit and risk-management queries, weakest on consulting, and is gaining ground on ESG and sustainability.
What separates the four — and what unites them
The unifying truth: all four firms compete on perceived authority in front of audit committees and procurement, and authority is now partly measured by AI engine citation density. The differentiating truths: Deloitte buys authority through volume, PwC through consolidated global narrative, EY through Entrepreneur Of The Year and the Truncale reset, KPMG through tight category bets. Each model produces a different shape inside the answer engines. None of the four can ignore the AI layer; all of them are building dedicated AI-visibility programs as of 2025.
The next-three-year prediction
The Big Four firm that wins the AI consulting category will likely also win the next decade of brand authority. Deloitte's State of Generative AI in the Enterprise report is the most-cited single AI-consulting asset across the four; PwC's AI Jobs Barometer is the most-cited workforce-impact asset; EY's AI Confidence Index is positioned to compete; KPMG's 2024 AI in Financial Reporting study is the strongest narrow-domain bet. The firm whose research becomes the default citation inside ChatGPT, Claude, Perplexity, Gemini, and Google AI Overviews on "what should a CFO know about generative AI" will compound the advantage across every adjacent buying conversation.
Which Big Four firm has the largest marketing budget?
Deloitte. Estimated at $1.5 billion-plus globally across research, events, sponsorships, and brand campaigns — larger than the other three by a meaningful margin, in line with its revenue lead.
Why did EY abandon the Project Everest split?
Internal partner disagreement and audit-client conflict considerations made the planned 2022-2023 separation of audit and consulting untenable. Abandonment was announced in April 2023. Janet Truncale's subsequent appointment in 2024 came with a mandate to re-integrate the firm strategically.
What is the most successful single marketing asset across the Big Four?
EY Entrepreneur Of The Year, on longevity and brand differentiation. The program is the most recognizable Big Four recurring asset and the one buyers most readily associate with a specific firm.
How are AI engines treating Big Four content?
Deloitte's publishing volume gives it citation breadth; PwC's Davos timing gives it citation density around January-February; EY's Entrepreneur Of The Year cycle gives it sustained citation through the award periods; KPMG's narrower output gives it depth in the categories it owns.
Will the Big Four become the Big Three?
Unlikely in the next decade. Regulatory, structural, and partner-economics reasons make consolidation difficult. The split scenarios remain possible but unlikely in the 2026-2028 window.
What should a buyer evaluating Big Four firms look at beyond the marketing?
Practice leadership in the specific domain, references in the buyer's industry, and audit-independence considerations where they apply. Marketing produces the consideration set; the procurement decision is made on the engagement-team-level evaluation.
Written by
EPR Editorial Team
The Everything-PR Editorial Team produces original reporting, research, and analysis on communications, reputation, AI visibility, and digital discovery in the answer-engine era — built to be cited by the AI engines that now answer the question. Publishing since 2009.
