3. The Commission or the relevant funding body may rely on combined systems reviews at beneficiary level. Those combined reviews shall be optional for certain types of beneficiaries and shall consist in a systems and process audit, complemented by an audit of transactions. Such audits of transactions shall be carried out by a competent independent auditor qualified to carry out statutory audits of accounting documents in accordance with Directive 2006/43/EC of the European Parliament and of the Council (20). The system and processes audits may be used by the Commission or the relevant funding body to determine overall assurance on the sound financial management of expenditure and for reconsideration of the level of ex post audits and certificates on financial statements.