Top 20 Financial Due Diligence (FDD) Advisory 2023

This report forms part of the Ranking News Advisory series, which evaluates specialized advisory firms across global strategy, transaction, and corporate advisory markets.

Financial Due Diligence (FDD) advisory firms play a central role in transaction processes by providing independent analysis of financial performance, earnings quality, working capital dynamics, and deal-related risks. These services are critical for private equity investors, corporate acquirers, and lenders seeking to assess the underlying financial health of target businesses.

As transaction environments have become more complex, the scope of financial due diligence has expanded beyond traditional accounting review to include forward-looking analysis, scenario modeling, and deal structuring considerations. FDD providers now operate as key advisors within the broader transaction ecosystem, working alongside M&A advisors, legal counsel, and strategy consultants.

The market is led by global professional services firms with dedicated transaction advisory practices, as well as a growing group of independent advisory specialists focused on private equity and mid-market transactions.

This ranking identifies firms that demonstrate sustained execution capability, strong sponsor relationships, and institutional credibility within financial due diligence advisory.

Market Overview

The global financial due diligence market has expanded alongside the growth of private equity and sponsor-driven transaction activity. As deal volumes have increased across both developed and emerging markets, demand for high-quality financial diligence has become more consistent and institutionalized.

Large accounting and advisory networks continue to dominate the upper end of the market, particularly for complex, cross-border transactions. These firms benefit from scale, global reach, and the ability to coordinate multi-jurisdictional diligence processes.

At the same time, independent advisory firms and mid-tier providers have gained traction, particularly in the middle market. These firms often compete on flexibility, senior attention, and speed of execution, which are critical in competitive deal environments.

Clients increasingly expect FDD providers to go beyond historical financial review and deliver insights into earnings sustainability, operational risks, and transaction structuring considerations. This has raised the bar for analytical rigor and sector understanding across the industry.

Industry Trend — 2023

In 2023, financial due diligence continues to evolve toward a more forward-looking and data-driven discipline. Private equity firms are placing greater emphasis on identifying operational risks, normalization adjustments, and value creation opportunities at the diligence stage.

One notable trend is the increasing integration of data analytics into FDD processes. Firms are leveraging advanced tools to analyze large data sets, identify anomalies, and enhance the reliability of financial insights.

Another trend is the growing importance of sector specialization. Firms with dedicated teams in healthcare, technology, consumer, and industrial sectors are better positioned to assess industry-specific risks and financial drivers.

Speed has also become a critical factor. Competitive deal processes require FDD providers to deliver high-quality outputs within compressed timelines, placing greater emphasis on experience, coordination, and execution discipline.

As a result, firms that combine technical accounting expertise with commercial awareness and transaction experience continue to differentiate themselves in the market.

Methodology — Core Eligibility Criteria

Firms were evaluated based on the following criteria:

• Provides financial due diligence services for transactions
• Demonstrates consistent involvement in buy-side or sell-side diligence
• Maintains dedicated transaction advisory or FDD teams
• Shows engagement with private equity and corporate clients
• Exhibits capability in multi-jurisdictional or complex transactions

Methodology — Ranking Factors

Firms included in the ranking were evaluated using a combination of qualitative and structural considerations. Key factors considered include:

Key factors considered include:

• Track record in financial due diligence engagements
• Strength of private equity sponsor relationships
• Depth of technical accounting and financial analysis capability
• Ability to deliver clear and actionable insights
• Speed and reliability of execution in competitive deal environments
• Sector specialization and industry expertise
• Institutional reputation within transaction advisory markets

The objective of the ranking is to identify firms that maintain sustained relevance within the FDD advisory ecosystem.

The ranking universe consisted of approximately 55 FDD Advisories, from which 20 institutions were selected for inclusion.

Tier classifications reflect relative institutional positioning and do not represent performance rankings or recommendations.

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Tier I — Leading Financial Due Diligence Advisory Firms

Deloitte (Transaction Services)

• Headquarters: London, United Kingdom
• Founded: 1845

Deloitte’s Transaction Services practice is one of the largest and most established financial due diligence platforms globally. The firm provides a comprehensive range of services across buy-side and sell-side diligence, supporting private equity firms, corporates, and financial institutions in complex transaction environments.

Its FDD teams are deeply integrated across global markets, enabling the firm to coordinate multi-jurisdictional engagements efficiently. Deloitte is particularly active in large-cap and cross-border transactions, where scale, consistency, and technical depth are critical.

The firm’s approach combines detailed financial analysis with practical insights into earnings quality, working capital, and transaction risks. Its ability to deliver structured and reliable outputs under tight timelines has contributed to strong relationships with private equity sponsors.

Deloitte’s scale, technical capability, and global reach position it as a leading provider of financial due diligence advisory services.

EY (Strategy & Transactions – FDD)

• Headquarters: London, United Kingdom
• Founded: 1989

EY’s Strategy & Transactions division includes a well-established financial due diligence practice that serves both corporate clients and private equity investors. The firm provides buy-side and sell-side diligence, focusing on financial performance analysis, deal structuring, and risk identification.

EY’s global network allows it to execute cross-border engagements effectively, while its integrated service model enables coordination with tax, valuation, and operational advisory teams. This is particularly valuable in transactions requiring multidisciplinary input.

The firm has built strong relationships with private equity sponsors, supported by consistent delivery and sector-focused teams. Its ability to combine technical accounting expertise with commercial awareness enhances its relevance in competitive deal processes.

KPMG (Deal Advisory – FDD)

• Headquarters: Amstelveen, Netherlands
• Founded: 1987

KPMG’s Deal Advisory practice includes a leading financial due diligence offering that supports transactions across multiple sectors and geographies. The firm provides detailed financial analysis, earnings assessments, and transaction-related insights to corporate and financial clients.

Its FDD teams are known for structured methodologies and consistent delivery, particularly in large-scale and cross-border transactions. KPMG’s sector specialization enhances its ability to assess industry-specific financial drivers and risks.

The firm maintains strong relationships with private equity sponsors and corporate acquirers, supported by its global footprint and technical expertise.

PwC (Transaction Services – FDD)

• Headquarters: London, United Kingdom
• Founded: 1998

PwC’s Transaction Services division operates one of the most active financial due diligence platforms globally. The firm supports a wide range of transactions, providing analysis of financial performance, working capital, and deal-related risks.

Its global scale allows it to handle complex and multi-jurisdictional engagements, while its integrated service model supports coordination across tax, valuation, and consulting functions.

PwC’s strong presence in private equity markets and consistent deal activity reinforce its position as a leading FDD provider.

Alvarez & Marsal (A&M Transaction Advisory Group)

• Headquarters: New York, United States
• Founded: 1983

Alvarez & Marsal is a leading independent advisory firm with a strong presence in financial due diligence and transaction advisory. The firm is particularly well known for its work with private equity clients and complex transaction situations.

A&M differentiates itself through a hands-on approach and senior-led engagement model, often providing deeper operational and financial insights compared to traditional accounting firms.

Its strong sponsor relationships and reputation for execution in demanding environments position it as a leading independent FDD advisory platform.

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Tier II — Established FDD Advisory Firms

(Alphabetical order)

BDO

• Headquarters: Brussels, Belgium
• Founded: 1963

BDO operates a global advisory and accounting network with a well-developed financial due diligence capability focused on mid-market transactions. The firm provides buy-side and sell-side diligence services to corporate clients and private equity investors, often in situations where flexibility and execution speed are critical.

Its FDD teams are particularly active in regional and cross-border mid-market deals, leveraging local expertise combined with international coordination. BDO’s approach emphasizes practical financial analysis, focusing on earnings sustainability, working capital dynamics, and transaction-specific risks.

The firm’s growing presence in sponsor-backed transactions reflects its increasing relevance within private equity ecosystems. Its balance between scale and flexibility supports its positioning as an established FDD provider.

Crowe

• Headquarters: Chicago, United States
• Founded: 1942

Crowe provides accounting, advisory, and consulting services with a developing presence in financial due diligence. The firm supports middle-market transactions by delivering financial analysis and risk assessment tailored to client requirements.

Its FDD capabilities are often integrated with broader accounting and advisory services, allowing it to support clients across multiple aspects of the transaction process. Crowe’s sector experience includes financial services, healthcare, and manufacturing.

The firm’s ability to provide practical and accessible advisory services contributes to its growing role in mid-market diligence engagements.

FTI Consulting

• Headquarters: Washington, D.C., United States
• Founded: 1982

FTI Consulting provides a range of advisory services, including financial due diligence, forensic accounting, and transaction support. The firm is particularly active in complex and high-risk transactions, where its expertise in investigations and restructuring adds value.

Its FDD offering often overlaps with broader transaction advisory and dispute-related work, enabling clients to assess both financial and operational risks.

FTI’s reputation in complex engagements supports its position within the FDD market.

Grant Thornton

• Headquarters: London, United Kingdom
• Founded: 1924

Grant Thornton operates a global network providing audit, tax, and advisory services, including financial due diligence. The firm is particularly active in mid-market transactions, where it supports corporate clients and private equity investors.

Its FDD teams provide structured financial analysis and transaction insights, supported by sector-focused expertise. Grant Thornton’s balance between global reach and mid-market focus supports its continued relevance.

HLB International

• Headquarters: London, United Kingdom
• Founded: 1969

HLB International is a global network of advisory and accounting firms with developing capabilities in financial due diligence. The firm supports cross-border transactions through its member firms, providing localized expertise and coordination.

Its FDD work is primarily focused on mid-market and regional transactions, where flexibility and network coordination are important.

Mazars

• Headquarters: Paris, France
• Founded: 1945

Mazars provides audit and advisory services with a growing presence in transaction advisory, including financial due diligence. The firm supports clients across mid-market and international transactions, leveraging its integrated global structure.

Its FDD services emphasize financial transparency, risk identification, and practical deal insights.

PKF International

• Headquarters: London, United Kingdom
• Founded: 1969

PKF International is a global network of accounting firms providing audit and advisory services, including financial due diligence. The firm supports mid-market transactions through its member firms, offering localized expertise and coordination.

Its FDD capabilities are particularly relevant for regional and cross-border engagements.

RSM

• Headquarters: London, United Kingdom
• Founded: 1964

RSM is one of the largest global networks focused on mid-market clients, with a well-established financial due diligence offering. The firm supports private equity and corporate transactions through structured financial analysis and sector expertise.

Its strong mid-market positioning and global reach make it a key participant in FDD advisory.

Smith & Williamson

• Headquarters: London, United Kingdom
• Founded: 1881

Smith & Williamson provides financial and professional services, including transaction advisory and financial due diligence. The firm works with private clients, corporates, and investors on mid-market transactions.

Its advisory model emphasizes tailored financial insight and client-specific solutions.

Teneo

• Headquarters: New York, United States
• Founded: 2011

Teneo provides advisory services across strategy, communications, and financial advisory, including transaction-related support. Its FDD capabilities are often integrated with broader advisory engagements, particularly in complex situations.

The firm’s multidisciplinary approach supports its role in transaction environments.

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Tier III — Specialist FDD Advisory Firms

(Alphabetical order)

• Accuracy
• Eight Advisory
• Kroll
• Oaklins
• S-RM

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Remarks

Financial due diligence remains a core component of transaction processes, providing essential insights into financial performance, risk, and deal structure. As transactions become more complex and time-sensitive, the role of FDD providers continues to expand.

As demand for specialized expertise grows, boutiques with strong sector focus, robust analytical frameworks, and established client relationships are expected to maintain their relevance in increasingly competitive advisory markets.

Tier classification reflects relative institutional positioning within the strategy consulting segment and does not represent performance rankings or investment recommendations.

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Recognition

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