Private Equity Investing in Professional Services: Top Firm…

Key Facts

• PE firms completed 118 deals in the US accounting sector alone between 2020 and 2025, deploying an estimated $30 billion into CPA and advisory businesses.
• Eleven of the top 30 US accounting firms have accepted private equity investment since 2021, with projections suggesting more than half will be PE-backed by end of 2025.
• European professional services deal volume rose 46% between 2019 and 2023, with UK and Continental markets remaining the most active globally.
• PE deal count in the sector climbed 17% in H1 2025 versus H1 2024, while deal value grew more than 40% over the same period.
• Buy-and-build consolidation dominates strategy: add-on acquisitions accounted for 74% of all US PE deals in 2024.
• Technology-enabled professional services firms attract EBITDA multiples 20-30% higher than traditional firms, driving sustained capital inflows.
• UK-based general partners hold approximately £178 billion in uncommitted capital earmarked for deployment over the next three to five years.

Professional Services PE Overview

Professional services firms have become one of private equity's most actively pursued investment categories. Accounting practices, law firms, management consulting businesses, financial advisory groups, and tax specialists share characteristics that are uniquely attractive to buyout firms: recurring revenue from mandatory annual engagements, highly fragmented markets with no dominant national player, and client relationships resilient enough to survive economic downturns.

The investment thesis rests on a simple structural dynamic. Over 60% of mid-sized consulting firms generate more than 70% of their revenue from repeat clients, and corporate clients rarely bring complex tax, audit, and advisory engagements in-house. PE investors see this revenue stickiness as the foundation for a buy-and-build platform that compounds returns through bolt-on acquisitions in fragmented local markets.

London and New York function as the twin hubs of global professional services private equity. London holds a regulatory head start through the Legal Services Act of 2007 and the Financial Reporting Council's mandate that the Big Four separate audit from non-audit operations. New York hosts Blackstone, New Mountain Capital, Stone Point Capital, and TowerBrook Capital Partners, while Chicago anchors major US accounting platforms including Baker Tilly, BDO USA, and Grant Thornton. Arizona has emerged as the primary US laboratory for law firm investment, licensing 136 Alternative Business Structure entities as of April 2025.

Professional Services PE: Firm Comparison

CVC Capital Partners leads the group with disclosed assets under management of EUR186 billion, making it the best-capitalized firm in this comparison. Most other active investors do not publish firm-level AUM for their professional services allocations specifically, so the table below ranks by deal prominence where AUM is unavailable.

Hg Capital, Cinven, and Inflexion represent the UK-centric buy-and-build cluster, where regulatory infrastructure is most developed. US-focused fund managers including Hellman & Friedman, New Mountain Capital, and Blackstone are executing larger platform buyouts enabled by accounting's Alternative Practice Structure framework. Apollo stands apart as the sector's primary debt capital provider rather than a traditional equity sponsor.

Top Picks by Investment Strategy

Largest Single Deal in Sector: Cinven, with the £1.5 billion acquisition of Grant Thornton UK's non-audit operations in April 2025, representing the highest confirmed transaction value in professional services PE to date.

Most Active US Accounting Investor: New Mountain Capital, which backed Grant Thornton US's non-audit unit in 2024 after completing a secondary sale of a major CPA platform to Blackstone for more than $2 billion.

Buy-and-Build Leader: Hg Capital, which assembled Azets from three founding firms in 2016 and has since completed seven or more bolt-on acquisitions to create a UK top-ten accountancy platform.

Structural Innovation Leader: TowerBrook Capital Partners, which pioneered the Alternative Practice Structure model for US accounting through the EisnerAmper transaction in 2021, separating the CPA-owned attest entity from the PE-owned advisory business.

Strongest Mid-Market Track Record: Horizon Capital, backing Dains in 2021 and executing five or more subsequent acquisitions including PSTAX, 3STAX, HSKS Greenhalgh, and Midlands-based Magma Chartered Accountants in 2024.

Top Carve-Out Specialist: CVC Capital Partners, which acquired Teneo (incorporating a Big Four restructuring practice) and is exploring EY Italy's consulting arm at EUR366 million in revenue, making it the most active buyer of Big Four divestiture assets.

Best Minority Investment Program: Bain Capital, deploying a $250 million minority stake in Sikich while preserving partner governance, a model increasingly preferred by professional services firms reluctant to cede board control.

Top Professional Services PE Firms in Detail

Hg Capital: The Buy-and-Build Architect

Hg Capital built the UK's Azets platform from a conviction that fragmented regional accounting markets reward decisive consolidation. Its 2016 merger of three founding firms created a nationally competitive accountancy business from scratch. Azets has since acquired Wilkins Kennedy, Tait Walker, Campbell Dallas, and Gorilla Accounting, cementing its position as a UK top-ten firm. Hg prioritizes organic integration between acquisitions rather than pure deal volume, a discipline that has made Azets one of the sector's most closely watched holdings.

Cinven: The Mega-Buyout Benchmark

The April 2025 acquisition of Grant Thornton UK's non-audit business for £1.5 billion established Cinven as the firm willing to deploy the largest single check in professional services PE history. Post-completion, Grant Thornton UK merged with Grant Thornton Ireland to create a 12,000-person multinational platform, and partners received average payouts of £682,000. For limited partners evaluating sector exposure, Cinven's transaction sets the benchmark for what institutional-scale capital can accomplish in a single professional services deal.

New Mountain Capital: The Serial Dealmaker

New Mountain Capital has built a documented track record of entry, value creation, and exit in US accounting. Its investment in a top-20 CPA firm preceded a secondary sale to Blackstone for more than $2 billion, one of the sector's first large-scale secondary buyouts. The firm then backed Grant Thornton US's non-audit unit in 2024, which subsequently acquired member firms in the UAE, Luxembourg, and the Cayman Islands. New Mountain Capital's ability to identify firms capable of rapid international expansion distinguishes it from investors treating professional services as a purely domestic consolidation play.

TowerBrook Capital Partners: The Regulatory Pioneer

TowerBrook's acquisition of EisnerAmper in 2021 required navigating federal accounting independence rules that prohibit non-CPA majority ownership of attest practices. The firm restructured EisnerAmper into two entities: a CPA-owned EisnerAmper LLP for regulated attest services and an investor-owned Eisner Advisory Group LLC for tax and consulting. PE sponsors across the US have since adopted this APS structure as the standard template for accounting transactions. PE-backed EisnerAmper now competes directly against the Big Four for talent, winning recruitment contests against much larger firms according to consultant analysis.

CVC Capital Partners: The Carve-Out Consolidator

CVC Capital Partners manages EUR186 billion across strategies, with professional services carve-outs representing a growing allocation. Its ownership of Teneo, which absorbed a Big Four restructuring services business, exemplifies the firm's approach: acquire a strategic advisory platform, then use it to absorb Big Four divestitures mandated by the Financial Reporting Council's audit separation rules. CVC's reported interest in EY Italy's consulting arm at EUR366 million in revenue signals continued appetite for this carve-out pipeline. Advisors structuring exit processes for Big Four consulting units treat CVC as the natural institutional buyer.

Hellman & Friedman: The Scale Investor

Hellman & Friedman's investment in Baker Tilly US, completed in 2024 alongside co-investor Valeas Capital Partners, was the largest private equity investment in the US CPA sector at the time of execution. The deal reflects the firm's preference for market leaders in fragmented professional verticals rather than early-stage platforms requiring heavy operational intervention. Founders and managing partners at large US accounting firms considering a PE process should treat Hellman & Friedman as the natural counterparty for transactions above $1 billion in deal value.

Blackstone: The Secondary Buyer

Blackstone's acquisition of a major national CPA platform from New Mountain Capital for more than $2 billion marked the sector's first high-profile secondary buyout and confirmed that PE-to-PE exits are viable at significant scale. Blackstone's involvement signals that professional services has matured as an asset class within large buyout portfolios, with the world's largest alternative asset manager willing to allocate from its flagship funds. LPs in Blackstone's real estate and credit vehicles may find parallel exposure to professional services increasingly embedded in broader Blackstone PE strategies.

Investment Trends Shaping Professional Services PE

Buy-and-Build Consolidation Accelerating

Add-on acquisitions accounted for 74% of all US PE deals in 2024, and professional services exemplifies this pattern. Fifty-five percent of PE-led professional services deals between 2021 and 2023 followed a buy-and-build strategy, using an initial platform purchase to enable subsequent bolt-on acquisitions. The fragmented nature of accounting, consulting, and advisory markets means that scale advantages compound rapidly: a 20-firm regional platform commands meaningfully better pricing, talent attraction, and cross-selling capabilities than a 5-firm one.

Digital Transformation and AI Premium

Digitally mature professional services firms command EBITDA multiples 20-30% higher than traditional firms, according to independent survey data. PE-backed platforms are accelerating technology adoption across cloud infrastructure, CRM systems, and AI-enabled service delivery to capture this multiple premium before exit. BCG estimates that 30% of finance executives expect AI and generative AI to deliver measurable value by end of 2025, and these executives engage the same accountants and consultants who must match their technological sophistication.

Regulatory Liberalization Creating New Entry Points

Arizona's elimination of Rule 5.4 in 2021 has produced 136 licensed Alternative Business Structure entities as of April 2025, with 59% of newly licensed entities in the 2024 cohort wholly owned by nonlawyers. The UK's Legal Services Act framework has enabled four law firms to publicly list on the London Stock Exchange. Each regulatory change creates a discrete wave of deal flow as previously restricted professional services firms gain access to PE capital for the first time.

Carve-Out Pipeline from Big Four Separations

The Financial Reporting Council's mandate for Big Four firms to separate audit from non-audit operations has produced a repeatable carve-out pipeline for PE investors. KPMG's pensions and wealth advisory practice became Isio, which subsequently acquired a Big Four pensions advisory business. KPMG's restructuring practice became Interpath Advisory, while another Big Four restructuring arm was absorbed by Teneo. CVC's reported pursuit of EY Italy's consulting unit suggests this pipeline continues generating investable assets.

ESOP as a Third Path

BDO USA established the first large public accounting firm Employee Stock Ownership Plan in August 2023, financed with $1.3 billion in debt from Apollo Global Management. The ESOP structure provides broad equity participation for employees and liquidity for retiring partners without surrendering control to an external GP. Apollo's willingness to provide debt capital at this scale validates professional services as a creditworthy sector. Managing partners across the top 30 US accounting firms who prefer partner control to PE governance are studying BDO's model closely.

How to Evaluate Professional Services PE Firms

Assess sector specialization before AUM. A fund with EUR186 billion in total managed capital may allocate only a small portion to professional services, while a mid-market firm like Horizon Capital may have deeper operator expertise in UK accountancy buy-and-build. Deal history is a better predictor of execution capability than fund size.

Scrutinize the deal structure on offer, not just the valuation multiple. Majority buyouts via a Topco/Newco corporate stack transfer governance to the PE board, while minority investments preserve partner control. APS structures in US accounting split attest and advisory into separate entities for regulatory compliance. Each structure carries different implications for day-to-day autonomy, compensation, and exit optionality, so partners should model all three scenarios before entering exclusivity.

For LPs evaluating sector-specific fund exposure, the key metrics are internal rate of return (IRR) and holding period. Professional services PE delivers average IRRs exceeding 20% with average holding periods of 4.7 years, comparing favorably to broad mid-market buyout benchmarks. Recurring revenue models prove more resilient through economic cycles than project-based businesses, reducing drawdown risk in stressed environments.

Red flags in due diligence include high partner concentration (client relationships tied to individuals who may exit post-transaction), defined benefit pension liabilities that are difficult to model accurately, and professional indemnity insurance costs that have risen sharply across the sector. Quality of earnings analysis is essential because many partnership accounts use cash or modified accrual methods requiring conversion to GAAP before institutional investors can underwrite them.

Which Firm Fits Your Needs?

Managing partners at large UK or US accounting firms with EBITDA above £5 million and a fragmented regional competitor base should engage Hg Capital and Horizon Capital for buy-and-build mandates, or Cinven and Hellman & Friedman for larger outright buyouts. Both UK-focused platforms have documented ability to execute complex LLP-to-corporate conversions and manage salaried member rule compliance without disrupting partner compensation structures.

LPs building diversified alternatives portfolios can access professional services exposure most directly through CVC Capital Partners, whose EUR186 billion fund platform includes confirmed positions in Teneo and potentially EY Italy's consulting arm. Investors seeking pure-play mid-market exposure to fragmented UK accountancy should examine Horizon Capital's track record on Dains, where five-plus bolt-on acquisitions in four years demonstrate repeatable execution.

Consulting firm founders and advisory business owners evaluating a partial liquidity event without full loss of control can reference Bain Capital's $250 million minority investment in Sikich and Further Global Capital Management's minority stake in Armanino as structural precedents. Both transactions preserved partnership governance while providing growth capital and retirement liquidity for senior partners, and both firms continued operating independently with PE-supported resources.

Methodology

This guide to private equity investing in professional services draws on publicly available deal announcements, regulatory filings, professional body data, and independent market research covering activity from 2020 through early 2026. Deal volume statistics draw on US accounting sector tracking covering 118 transactions. European deal data reflects independent analysis of professional services investment activity between 2019 and 2023. Firm profiles are based only on confirmed transactions and publicly disclosed deal terms. Where AUM or deal values are not publicly confirmed, those figures are omitted rather than estimated. Firms are evaluated on their documented activity in professional services specifically, not on total fund size.