Last updated: 21 April 2026
Short answer: the Principles for Responsible Investment are six voluntary principles that help investors incorporate ESG issues into investment decisions, ownership practices, portfolio-company disclosure, industry practice, collaboration, and reporting. For investment teams, the real work is turning those principles into policy, due diligence, portfolio monitoring, engagement, and credible investor reporting.
The Principles for Responsible Investment, often shortened to PRI, are one of the best-known responsible investment frameworks. They were developed by investors and are supported by the United Nations. PRI’s own framing is practical: the principles are not a single investment product or a guarantee of impact. They are a framework for incorporating environmental, social, and governance considerations into investment practice.
This matters because many investors now face sustainability expectations from LPs, beneficiaries, regulators, portfolio companies, and internal investment committees. The six principles provide a useful structure, but they only create value when they are translated into how the investment team actually works.
What the PRI principles are for
The PRI principles are designed for investors, including asset owners, investment managers, and service providers. They are voluntary and broad by design. That flexibility is useful because responsible investment looks different across public equities, private equity, venture capital, infrastructure, credit, real assets, and multi-asset portfolios.
For a private investor or portfolio manager, the principles can help answer practical questions:
- How should ESG issues be considered during investment analysis?
- How should ownership or influence be used after investment?
- What sustainability information should be requested from portfolio companies?
- How should expectations be communicated to managers, advisers, and service providers?
- Where can investors collaborate without losing their own strategy or judgment?
- How should responsible investment activity and progress be reported?
The principles are most useful when they sit inside the investment process, not beside it.
The six principles in practical terms
Principle 1: Incorporate ESG issues into investment analysis and decisions
This principle is about investment analysis. ESG issues should be considered where they are financially relevant, strategically relevant, or important to the investor’s mandate. The output should be decision-useful, not a generic ESG score pasted into an investment memo.
Practical implementation can include:
- Adding ESG questions to screening and due diligence templates
- Identifying sector-specific sustainability risks and opportunities
- Reviewing climate, workforce, governance, supply chain, and customer requirement exposure
- Documenting how ESG findings affect valuation, risk, covenants, ownership plans, or investment committee decisions
For private portfolios, this often means creating a focused diligence process that can be applied consistently without overwhelming management teams.
Principle 2: Be active owners and include ESG issues in ownership practice
Responsible investment is not finished once the investment is made. Investors can use ownership, board influence, voting rights, lender engagement, or management relationships to support better practices.
In private markets, active ownership may involve setting expectations at onboarding, reviewing sustainability progress at board or operating reviews, helping companies improve data quality, and building practical action plans. The point is not to ask for reports for their own sake. The point is to improve governance, resilience, risk management, and operating performance.
Principle 3: Seek appropriate ESG disclosure from investees
Investors need reliable information from the companies, funds, or assets they invest in. This does not mean every company should publish a full sustainability report immediately. It means the investor should ask for information that is appropriate to the company’s size, sector, risk profile, and stakeholder requirements.
Disclosure requests may cover:
- Governance and policy ownership
- Scope 1 and Scope 2 emissions, with relevant Scope 3 categories where needed
- Workforce, health and safety, diversity, or human rights indicators
- Customer sustainability requests and supplier requirements
- Climate risk exposure and resilience planning
- Material incidents, controversies, or compliance issues
Good disclosure starts with clear data requests, evidence requirements, and a methodology for estimates or gaps.
Principle 4: Promote responsible investment within the investment industry
This principle pushes investors to normalize responsible investment across the market. For an investment firm, this can affect manager selection, consultant relationships, mandates, reporting requirements, and service-provider expectations.
Implementation may include asking external managers how they integrate sustainability, including responsible investment expectations in mandates, selecting advisers with relevant expertise, and making sure ESG language in investment documents is specific enough to be implemented.
Principle 5: Work together to improve implementation
Many sustainability issues are too large for one investor to address alone. Collaboration can help investors share practice, improve data quality, engage with companies, and support clearer market standards.
Collaboration does not mean every investor has the same strategy. It means investors can learn from peers, participate in industry initiatives, and support better information flows while still making their own investment decisions.
Principle 6: Report on responsible investment activity and progress
Reporting is what makes implementation visible. Investors should be able to explain what they said they would do, what they actually did, what changed, and where gaps remain.
For a private investment firm, responsible investment reporting may include policy updates, due diligence activity, portfolio company data coverage, engagement activity, emissions data, incidents, improvement plans, and case examples. The key is to avoid overclaiming. Reporting should match the evidence.
How to turn the principles into an operating model
The six principles can sound abstract until they are translated into workstreams. A practical operating model may include:
- Policy: define responsible investment beliefs, scope, responsibilities, exclusions or restrictions, and governance.
- Diligence: add sustainability questions and escalation rules to deal screening and investment committee materials.
- Portfolio baseline: collect core ESG and emissions data from portfolio companies or assets.
- Engagement: set practical action plans with investees and review progress periodically.
- Data management: standardize templates, evidence requirements, assumptions, and quality checks.
- Reporting: prepare investor-facing reporting that explains methods, coverage, progress, and limitations.
This operating model should be proportional. A small fund does not need the same infrastructure as a global asset owner, but both need clarity on who owns the process and how the information affects decisions.
What smaller or private-market investors should watch
Smaller investment teams often struggle because responsible investment work is split across investment professionals, operations, finance, legal, and external advisers. Several issues deserve attention.
Do not rely on generic scores alone
Scores can be useful inputs, but they rarely explain the exact issue, evidence, or action needed for a specific company. Use them as signals, not substitutes for judgment.
Keep portfolio companies engaged
Portfolio companies may see sustainability requests as extra administrative work. Explain why information is needed, how it will be used, and which actions matter most.
Separate policy from proof
A responsible investment policy is only the starting point. Investors also need records showing how the policy was used in diligence, ownership, and reporting.
Make reporting honest
Responsible investment reports should disclose progress and limitations. It is better to explain data coverage and improvement plans clearly than to imply that every company is already mature.
How the principles connect to Keslio’s investor services
Keslio supports investors that need to turn responsible investment ambition into practical systems. This can include investment strategy development, portfolio sustainability management, portfolio company data collection, GHG emissions calculations, and investor-facing reporting and communications.
For investors working with the PRI principles, the priority is often implementation: creating templates, assigning responsibilities, collecting evidence, engaging portfolio companies, and producing reporting that can withstand scrutiny.
Bottom line
The six Principles for Responsible Investment are a useful framework, but the value comes from implementation. Investors need to connect the principles to their investment process, ownership model, portfolio-company expectations, and reporting rhythm.
A practical responsible investment system should help the investment team make better decisions, support portfolio companies, improve data quality, and communicate progress without overstating what has been achieved.
