HM Treasury and Chancellor Rachel Reeves announced further Green Book investment appraisal changes on 30 June 2026, including consistent publication of major business cases and support for £900 million of local growth funding over four years.
The announcement was made through a letter to mayors one year after the Chancellor began a review of the Green Book, the government’s guidance on value for money in public investment decisions. The update sets out how central government intends to assess projects across different parts of the UK.
The reforms cover national appraisal guidance, place-based business cases and transparency around major programmes. They are linked to the government’s aim of supporting regional growth and improving confidence in how public money is allocated.
Green Book Reforms Broaden Investment Appraisal
HM Treasury said the Green Book was updated in February so public investment decisions are not judged only by single measures such as benefit-cost ratios. The guidance now requires departments to consider wider economic, social and local growth impacts when assessing proposals.
Rachel Reeves wrote to mayors to update them on action taken after the Green Book review. The Treasury said the reforms are intended to give under-invested communities a stronger basis for making the case for government support.
- Timing: the letter to mayors was issued on 30 June 2026.
- Guidance: the Green Book was updated in February 2026.
- Scope: the reforms apply to public investment appraisal across the UK.
Updated Appraisal Rules Broaden Value For Money
The updated approach allows government to consider impacts beyond a narrow financial calculation. HM Treasury said this can include factors such as the business environment and areas with higher levels of innovation.
The change means wider local growth effects can be considered when public investment is assessed. This gives departments a broader framework for weighing how projects may affect jobs, prosperity and regional development.
Green Book Appraisal Changes
| Area | Change | Context |
|---|---|---|
| Value for money | Broader assessment | Beyond single ratios |
| Local growth | Wider impacts included | Jobs and prosperity |
| Innovation | Considered in appraisal | Supports growth assessment |
Discount Rate Review And Business Case Changes Published
HM Treasury has published findings from an independent review into the discount rate. The department said the findings support a fairer view of long-term investment decisions.
Business case guidance has also been streamlined and reduced by more than half. The government said the change is intended to reduce unnecessary red tape and cut through administrative complexity in public investment processes.
Place-Based Business Cases Put Local Priorities Into Appraisal
The government said it is working with regional leaders in Plymouth, Birmingham, Liverpool and Port Talbot on place-based business cases. These cases are intended to put local priorities and local expertise at the centre of appraisal.
In Plymouth, work is focused on maximising the impact of government defence investments. In Birmingham, the work relates to coordinated investment in health, housing and skills.
Liverpool’s business case is focused on unlocking infrastructure investment to drive growth and increase housebuilding. Port Talbot’s work is focused on breaking down barriers in the system to growth.
- Plymouth: defence investment impact is being assessed.
- Birmingham: health, housing and skills are being coordinated.
- Liverpool: infrastructure and housebuilding are the focus.
- Port Talbot: growth barriers are being reviewed.
Place-Based Business Case Areas
| Place | Focus | Purpose |
|---|---|---|
| Plymouth | Defence investment | Maximise impact |
| Birmingham | Public services | Coordinate investment |
| Liverpool | Infrastructure | Drive growth |
| Port Talbot | Growth barriers | Improve delivery |
Transparency Measures Cover Major Projects
HM Treasury said business cases for major projects and programmes are being published consistently for the first time. The measure is intended to show the public how decisions are made before major investment proceeds.
The department said this approach is designed to strengthen confidence that public money is being assessed properly. It also gives readers clearer information about how government links investment choices to expected public value.
Reforms Linked To Northern Powerhouse Rail And Local Growth Funding
HM Treasury said the reforms will shape decisions on projects such as Northern Powerhouse Rail. Wider considerations, including local growth, jobs and prosperity, will be taken into account when such projects are assessed.
The changes will also support mayors as they invest £900 million of local growth funding over the next four years. HM Treasury said this will help regional leaders use funding more effectively within the updated appraisal system.
Ministerial Comments
Rachel Reeves, Chancellor of the Exchequer said;
“This work sits at the heart of the government’s commitment to drive growth and increase living standards in every region. I am grateful for the continued partnership between central government and mayors in shaping and delivering this crucial agenda.”
“While there is more to do to fully embed these changes, we are on the path to building a system that supports better decisions, strengthens confidence in how investment is allocated, and helps deliver the long-term growth that communities across the UK both need and deserve.”
The Green Book reforms set out a wider approach to public investment appraisal, with regional impacts, long-term decisions and business case transparency placed within the same framework. HM Treasury said the changes will affect major programmes and local growth funding, while place-based business cases in four areas will test how local priorities can be reflected in government decisions.
Sources: HM Treasury and The Rt Hon Rachel Reeves MP.
Prepared by Ivan Alexander Golden, Founder of THX News, an independent news organisation delivering timely insights from global official sources. Combines AI-analysed research with human-edited accuracy and context.
