A range of business structures and partnership arrangements between the public and private sector. PPPs can cover all types of collaboration across the interface between the public and private sectors to deliver policies, services and infrastructure, including joint ventures and concessions, outsourcing and the sale of equity stakes in state-owned businesses.

The most common form of PPP in the UK was PFI (private finance initiative), which was introduced in 1992. However, in its 2018 Budget, the government announced that it was ceasing to use PFI for future public service projects.