In this paper, we explore the interactions between supply chain planning and financial planning. To do so, we investigate the integrated business planning (IBP) process as a suitable interface between them. We focus on the French business culture. First, we provide the results and conclusions of a survey on the structure and details of the sales and operations planning (S&OP) processes of five top French multinational corporations and the extent to which finance is integrated into these processes. These companies have achieved a revenue of over 16 billion euros in 2020. Then, we conclude on the steps that the participating companies have implemented to transition from the traditional S&OP process to the complete IBP process, and thus on the steps that remain to be taken. We note that all participating companies have taken their first steps towards adopting an integrated business planning approach. They have all embraced scenario analysis. However, they are lagging behind on the other steps that require cross-functional and cross-company collaboration, such as financial integration. Finally, we define how the IBP process interacts with financial planning on four fronts, namely revenue and costs budgeting, monthly updates to budgets, capital expenditures budgeting, and working capital requirements planning.