The process of conducting financial audits and other checks for the purpose of verifying whether the costs presented in the financial statements have been incurred in accordance with set procedures and are eligible costs. These audits and checks are carried out in order to confirm the legality and regularity of all related transactions. It involves an depth analysis of the costs claimed by a group of beneficiaries/ stakeholders supported by reliable and relevant evidence. Generally, the objective of such audits/ checks is to verify compliance of implementation of a specific process or actions (projects), undertaken under a program or plan, through financing decisions by the implementing party.

In specific contexts, “a posteriori control” may denote multiple meanings including:

• Audits undertaken by supreme audit institutions (SAIs) with a judicial power, whereby the records of parties who have personal responsibility for the use of public funds are examined and judged for compliance.
• Financial audits, including checks on documentation relating to a set of transactions, in order for SAIs to report on the state accounts and provide evidence for the legislature to before issuance of discharge or opinion.
• Performance audits, in relation to public expenditure and an economy’s state of functioning (efficiency and effectiveness).

It is also known as a posteriori audit or ex-post control.