Several Member States sent questions related to requests for interim payments and payments of the final balance and the method for calculation of the subsequent EC contribution in the framework of Regulation (EC) No 1083/2006. This note aims to provide clarifications on the calculation of the EC co-financing due from the Structural Funds and the Cohesion Fund (hereinafter referred to as "the Funds") under the 2007-2013 programming period, as well as the related audit issues.