PPP Definitions Compared: World Bank, OECD, EU and IMF

There is no single, universally accepted PPP definition. The World Bank, OECD, IMF, European Commission and others each describe public-private partnerships slightly differently, and some countries also define PPPs in law. Yet beneath the differences sits a clear consensus: a PPP is a long-term contract in which a private party takes on significant risk and responsibility for a public asset or service, and is paid according to performance.

This article compares the leading PPP definitions, explains what they share and where they differ, and sets out the definition used in the 2026 APMG PPP Certification Guide.

Why the definition of a PPP matters

How a PPP is defined is more than an academic question. It determines which projects fall under a country's PPP law and approval process, which ones must undergo value for money and fiscal risk assessments, how projects are recorded in government accounts, and what data appears in international databases. A loose definition can let poorly structured deals escape scrutiny; an overly narrow one can exclude useful contract forms.

The leading PPP definitions compared

World Bank (PPP Reference Guide 3.0)

The World Bank's definition is the most widely used by practitioners:

"A long-term contract between a private party and a government entity, for providing a public asset or service, in which the private party bears significant risk and management responsibility, and remuneration is linked to performance."

It is deliberately broad. It covers new infrastructure, upgrades of existing assets and the management of existing infrastructure or services, and it does not require private finance.

OECD

The OECD describes a PPP as an agreement between government and one or more private partners (which may include operators and financers) under which the private partners deliver a service in a way that aligns the government's service delivery objectives with the private partners' profit objectives. It stresses that the effectiveness of this alignment depends on a sufficient transfer of risk to the private partners.

International Monetary Fund (IMF)

The IMF defines PPPs as arrangements in which the private sector supplies infrastructure assets and services that have traditionally been provided by government. It highlights two characteristics beyond private construction and financing: an emphasis on service provision, and investment by the private sector, with significant risk transferred from government. The IMF's angle reflects its focus on fiscal risk and public accounts.

European Commission

The European Commission notes that PPP is not defined at EU level. In general, the term refers to forms of cooperation between public authorities and business that aim to ensure the funding, construction, renovation, management and maintenance of infrastructure, or the provision of a service.

European Investment Bank and Standard & Poor's

The EIB uses PPP as a generic term covering a wide variety of arrangements, from loose, informal and strategic partnerships to DBFO-type service contracts and formal joint ventures. Standard & Poor's describes a PPP as any medium- to long-term relationship between the public and private sectors involving the sharing of risks and rewards of multi-sector skills, expertise and finance to deliver desired policy outcomes.

Comparing the definitions side by side

The pattern is clear. The narrower, practitioner definitions (World Bank, OECD, IMF) converge on long duration, significant risk transfer and incentives linked to performance. The broader institutional definitions (EC, EIB) use PPP as an umbrella for almost any public-private cooperation.

The definition used in the 2026 PPP Guide

The APMG PPP Certification Guide, which underpins the CP3P certification, adopts the World Bank's broad definition for PPPs in general. It then adds a narrower definition for its main focus, the private finance PPP:

"A long-term contract between a public party and a private party for the development (or significant upgrade or renovation) and management of a public asset (including potentially the management of a related public service), in which the private party bears significant risk and management responsibility throughout the life of the contract, provides a significant portion of the finance at its own risk, and remuneration is significantly linked to performance and/or the demand or use of the asset or service so as to align the interests of both parties."

Each phrase in this definition corresponds to one of the essential features of a PPP contract, which is why CP3P candidates are expected to know it well.

When a PPP is a legal term

In some countries PPP is a legally defined type of contract. Where it is, the legal definition is often narrower than the Guide's. Several jurisdictions reserve the term PPP for contracts paid mainly by government, and call user-pays contracts "concessions". This mirrors the approach of the European System of Accounts. In these countries, a project can meet the international PPP definition without being a PPP under national law.

Other countries use different names entirely, often for political reasons, to distinguish PPPs from earlier privatisation programmes. Mexico, for example, has referred to projects for the provision of services (PPS), and Peru to co-financed concessions. The article on PPP nomenclature around the world explores these naming conventions.

What every definition excludes

Whatever definition is used, some arrangements are consistently outside it. A PPP is not privatisation, which permanently transfers ownership and responsibility to the private sector. Nor is a short-term construction contract or a contract with a government-owned company that bears no real risk. The common thread is a continuing partnership with genuine risk transfer.

This article is part of our PPP Fundamentals: The Complete Guide to Public-Private Partnerships.

Key takeaways

• There is no universal PPP definition, but the World Bank, OECD and IMF agree on the core: long term, significant risk transfer and performance-linked pay.
• The World Bank definition is broad and does not require private finance; the IMF puts more weight on private investment and fiscal risk.
• The 2026 PPP Guide uses the World Bank definition generally and a narrower "private finance PPP" definition for most of its content.
• National laws may define PPPs more narrowly, often separating government-pays PPPs from user-pays concessions.
• Always check which definition a law, database or report is using before comparing PPP data.

Go further

Want a structured grounding in these concepts? The CP3P Foundation course covers PPP definitions, models, the PPP process cycle and the essentials of project finance, aligned with the 2026 PPP Guide, and prepares you for the internationally recognised CP3P Foundation exam.

Related reading

• PPP Fundamentals: The Complete Guide to Public-Private Partnerships
• What Is a Public-Private Partnership (PPP)? A Complete Guide
• The Essential Features of a PPP Contract
• What Is a Private Finance PPP?
• PPP vs Privatization: What Is the Difference?
• The Role of Multilateral Development Banks in PPPs
• PPP Nomenclature Around the World: PFI, P3, APP and More

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