The modern supply chain management relies on efficient logistics operations to minimize transportation costs, improve delivery times, and ensure product availability. In our work, we introduce the demand swapping problem, which aims to reduce transportation costs in logistics networks. The innovation in this approach lies in the ability for clients to satisfy demands through the regular process or by swapping demands with each other, provided that there is a prior agreement. We have developed a mathematical model to address this problem. Our computational results demonstrate high-quality outcomes, with transportation costs reduced by over 50% for the instances used, and with low computational times.