Mobilising the Impact Economy as Partners in National Renewal
The Social Impact Investment Advisory Group (SIIAG), established in January 2025, has completed its mandate and submitted its final report to the UK government. The report provides a practical roadmap for creating a more strategic partnership between the government and the impact economy to drive inclusive growth across the UK.
The Group was set up by HM Treasury (HMT) and the Department for Culture, Media and Sport (DCMS). The Impact Investing Institute was pleased to contribute to the SIIAG through the membership of its Chair, Kieron Boyle OBE, and by providing support for the working groups that the Advisory Group set up to develop its recommendations.
Key Findings and Recommendations
The SIIAG’s final report, titled Mobilising the impact economy as partners in national renewal, calls on the government to partner with the impact economy to unlock billions in capital to address national challenges like child poverty, clean energy, and affordable housing.
The report’s central idea is the adoption of a ‘mobilisation mindset’, where government acts as a catalyst, using public funds and a co-design approach to attract private and philanthropic investment, share delivery, and scale solutions that improve outcomes for people.
The report is structured around three key pillars:
- Organising to mobilise and support the impact economy with sustained political leadership and the creation of an Office for the Impact Economy to coordinate action across government and provide a clear ‘front door’ for external partners.
- Embedding the mobilisation mindset by adopting a ‘match first/leverage approach’ as a core principle for policy design, business cases, and procurement, along with accelerating momentum through flagship projects.
- Unlocking resources and participation at scale with targeted reforms to clarify fiduciary duties for pension schemes, modernise Gift Aid, and integrate philanthropy into wealth advice to unlock further capital and corporate resources.
The report notes that the UK’s impact economy already stewards £106 billion in assets, with at least £42 billion of existing capital already aligned with key government priorities.
The SIIAG also helped shape the landmark £500 million Better Futures Fund announced in summer 2025, which is set to support vulnerable children and families through collaboration between government, communities, and impact investors.
Social Impact Investment Advisory Group
The Social Impact Investment Advisory Group (SIIAG) was established in January 2025 by HM Treasury (HMT) and the Department for Culture, Media and Sport (DCMS), marking a new chapter in how the UK government and impact economy can work together to address society’s most pressing challenges.
The focus of the SIIAG is to:
- Provide advice on effective ways for Government to use funds to mobilise social impact capital, making recommendations for the objectives, design and intended social outcomes of one or more Impact Investment Vehicles to announce at the conclusion of the Spending Review (SR) in June 2025. Funds in scope will include, but are not limited to, social outcomes partnerships and match-funded philanthropic or other capital.
- Review existing work on impact capital across government and provide views on the long- term future and direction of this work, aligned with the missions.
For more information about the SIIAG, please visit gov.uk. Please see below for further information about the working groups and how you can get involved.
Working groups
The SIIAG has chosen to support its’ work through four self-organising working groups with distinct but complementary areas of focus. The working group structure has been established to help with the vital task of gathering perspectives and expertise from across the impact economy. Working groups bring together, as well as engage with, representatives from across the impact economy, including those deploying capital as well as those receiving it, such as social enterprises, charities, and other purpose-driven businesses operating across the UK, regionally, and locally.
The working groups will report their recommendations to the SIIAG, which will meet monthly through June 2025. The SIIAG will determine which recommendations to put forward to government.
The four working groups are designed collectively to address the full pathway for mobilising, structuring, and deploying impact capital to support government missions:
- Immediate fund and impact investment vehicle design for government priorities: Advising on the government’s development of an investment-backed outcomes fund and the structuring of the vehicle, with potential for replication across policy areas. The group is led by Stephen Muers, CEO of Better Society Capital.
- Opportunity areas for impact capital: Identifying immediate opportunities to deploy impact capital effectively across national missions. The group will prioritise areas that are near-term and actionable. The group is led by Kieron Boyle, Chair of the Impact Investing Institute and Chief Executive of the 100x Impact Accelerator.
- Understanding and attracting the full range of impact capital: Defining requirements for effective impact capital flow into national priorities. This includes understanding sources, scale, and pace of impact capital, including consideration of both domestic and international capital flows into the UK. The group is led by Caroline Mason, CEO of Esmée Fairbairn, and Alan Smith from the First Church Estates Commissioners, Church Commissioners.
- Coordination between government and impact capital: Advising on models for effective partnerships and coordination between government and impact capital, including on organisational models to take advantage of and enable effective impact capital partnerships. The group is led by Dom Llewellyn, Head of the Impact Economy Collective, and Neil Heslop, CEO of Charities Aid Foundation
If you would like to learn more about the working groups or get involved, please contact policy@impactinvest.org.uk
