Ex post controls
Article 22
1. The authorising officer may put in place ex post controls to detect and correct errors and irregularities or operations after they have been authorised. Such controls may be organised on a sample basis according to risk and shall take account of the results of prior controls as well as cost-effectiveness and performance considerations. The ex post controls may be carried out on the basis of documents and, where appropriate, on the spot. 2. The ex post controls shall be carried out by staff other than that responsible for the ex ante controls. The staff responsible for the ex post controls shall not be subordinate to the members of the staff responsible for the ex ante controls. Authorising officers responsible and staff responsible for budget implementation shall have the necessary professional skills.