Resilient deal flow. PE-led consolidation. A firmer compliance baseline.
H1 2026 recorded 110 ESG consulting transactions, holding deal flow close to the record levels of 2025 despite a challenging macro environment and regulatory recalibration in both the US and Europe. Public market valuations fell over the half; private market appetite for specialist capability did not.
Based on analysis of 732 ESG consulting transactions completed since 2021, Equiteq’s ESG Consulting Valuation & M&A Update sets out where deal flow is concentrated, what buyers are paying in public and private markets, and how the regulatory reset is reshaping demand.
Market Outlook
Global ESG consulting revenue is forecast to reach $84bn by FY28, a 10.3% CAGR from 2020. Regulation and investor transparency expectations continue to underpin that growth, even as the near-term picture has been redrawn: Omnibus I raised CSRD thresholds, CS3D transposition moved to July 2027, and the SEC has proposed rescinding federal climate-disclosure rules in full. California and New York state regimes still bite, companies are continuing their disclosure preparations, and reporting is shifting towards audit-grade data and assurance. Near-term consultancy demand is dampened, but the compliance baseline continues to expand.
Buy-side activity remains led by private equity buy-and-build, alongside strategic consolidators acquiring specialist capability in reporting and compliance, natural capital and marine, and nuclear and energy-transition engineering. Proprietary data and modelling capability commands a premium. With 80% of H1 2026 targets employing fewer than 100 people, the market remains fragmented enough to sustain platform building through H2.
What’s Inside the Report
- Global ESG consulting market sizing and growth outlook to FY28
- H1 2026 deal flow, deal themes and the outlook for H2
- Private equity versus strategic buyer activity, and PE buy-and-build platforms
- Public and private valuation benchmarks across consulting, engineering, software and TIC services
- Regional deal concentration across North America, UK&I, Continental Europe and Oceania
- The ESG ecosystem map, from global industry leaders to emerging boutiques
Key Findings
732 ESG consulting transactions have been completed since 2021, including 110 in H1 2026. Deal volumes grew at a 43% CAGR between 2021 and 2025, and FY26 is tracking at 204 transactions annualised against 214 in FY25.
Private equity and PE-backed platforms account for 56% of transactions (412 of 732 deals since 2021), with strategic buyers making up the remaining 44%. Within PE activity, 79% are bolt-on acquisitions to existing platforms and 21% are platform buyouts.
The market is highly fragmented at the target level. 80% of H1 2026 targets employed fewer than 100 people, up from 66.8% in H1 2025, and 68% employed fewer than 50.
Private transactions completed since 2021 have averaged 11.6x EV/EBITDA in aggregate. Private equity buyers have paid slightly more than strategic acquirers, at 12.1x against 11.2x.
Public ESG and sustainability firms trade at an average of 10.1x EV/CY26E EBITDA. By segment: TIC and environmental compliance at 12.5x, engineering and environmental services at 10.6x, sustainability consulting at 9.1x, and sustainability IT solutions and services at 7.0x.
Yes, in public markets. Median NTM EV/EBITDA across the sustainability landscape fell 12% over H1 2026, from 14.2x in January to 12.6x in July, with sustainability consulting down 22% from 15.3x to 11.9x. Private markets have held firmer, and at 11.6x now command a premium over the 10.1x public average.
Global ESG consulting revenue is forecast to reach $84bn by FY28, up from $38bn in 2020, a 10.3% CAGR. Environmental and social consulting is expected to grow at approximately 8% CAGR between 2025 and 2028. ESG roles have tripled since 2018 to around 75,000 in 2025.
North America accounts for 37% of transactions and UK and Ireland a further 25%. The US has recorded 237 deals since 2021 and Europe 367, with Oceania adding 38.
Download the ESG Consulting Valuation & M&A Update – September 2026 for the full deal list, valuation benchmarks by segment, the active buyer landscape and the H2 2026 outlook.