1. Audits on the use of the Union contribution carried out by persons or entities, including by others than those mandated by the Union institutions, bodies, offices or agencies shall form the basis of the overall assurance pursuant to Article 127 of the Financial Regulation.
2. The control system shall ensure an appropriate balance between trust and control, taking into account administrative costs and other costs related to control at all levels.
3. Audits of expenditure shall be carried out in a consistent manner in accordance with the principles of economy, efficiency and effectiveness.
4. As part of the control system, the audit strategy may be based on the financial audit of a representative sample of expenditure. That representative sample shall be complemented by a selection based on an assessment of the risks related to expenditure.
5. Actions that receive cumulative funding from different Union programmes shall be audited only once, covering all programmes concerned and their respective applicable rules.