The collaboration contract between the public sector and the private sector is a type of contract related to the public sector contracting regime "Public Sector Contracting (Spain)") in Spain. Its essential regulation was contained in Law 30/2007, of October 30, on Public Sector Contracts, in the Text Revised by Royal Legislative Decree 3/2011, of November 14 and currently this type of contract is obsolete, according to Law 9/2017, of November 8, on Public Sector Contracts, by which the Directives of the European Parliament and the Council are transposed into the Spanish legal system. 2014/23/EU and 2014/24/EU, of February 26, 2014.

The purpose of the collaboration contract is to carry out a global and integrated action, in which two objective elements must come together. Firstly, the financing of intangible investments, works or supplies necessary to fulfill certain public service objectives or related to actions of general interest.[1]​.

Regarding the second objective element that characterizes the contract, the Law requires that it be one of the following assumptions:[1]​.

The Public Sector Contracts Law establishes an important limit for collaboration contracts, stating that they will only be used when public needs cannot be satisfied through another type of contract, thus giving it a subsidiary nature.[2]​.