1.   The control system set up for the implementation of this Regulation shall be so designed as to provide reasonable assurance of achieving sufficient reduction and adequate management of the risks relating to the effectiveness and efficiency of the operations as well as the legality and regularity of the underlying transactions, taking into account the multi-annual character of programmes as well as the nature of the payments concerned.

2.   The control system shall ensure an appropriate balance between trust and control, taking into account administrative and other costs of controls at all levels, especially for participants, so that the objectives of Horizon 2020 can be achieved and the most excellent researchers and the most innovative enterprises are attracted to it.

3.   As part of the control system, the audit strategy for expenditure on indirect actions under Horizon 2020 shall be based on the financial audit of a representative sample of expenditure across Horizon 2020 as a whole. That representative sample shall be complemented by a selection based on an assessment of the risks related to expenditure.

Audits of expenditure on indirect actions under Horizon 2020 shall be carried out in a coherent manner in accordance with the principles of economy, efficiency and effectiveness in order to minimise the audit burden on the participants.