A contribution is a tax that must be paid by the taxpayer or beneficiary of an economic benefit, the justification of which is the obtaining by the taxpayer (citizen recipient) of a benefit or an increase in the value of his assets, as a consequence of the performance of public works or the establishment or expansion of public services. It is paid for any improvement made, although there must not necessarily be proportionality between what was paid and the advantages received.[1]​[2]​.

Contributions can be established at the state, regional or local level, but it is in the latter where they reach their best expression and meaning, because it is easier to indicate a global quota to be distributed among the population of a certain municipal sector than in higher areas, since it is in municipal works and services where citizens are most closely affected and where the most special benefit or interest is revealed, with the aim of turning it into a point of reference for taxation and payment of State burdens.

They are usually considered direct taxes, especially the land tax, land tax or tax on real estate of a rural or urban nature.[3]​.

This tax is determined by the State through a law, and corresponds to a percentage of the tax valuation of the property or real estate.

Social contributions or improvement contributions are also called contributions, which are usually also called social contributions (the percentage of salaries that are paid to employers and workers to finance Social Security, unemployment insurance, retirement insurance, work accident insurance, disability insurance, sickness insurance, or any other type of contingency).[4]