Single use plastic products (SUPs) are a primary cause of plastic pollution causing significant environmental harm. These products have little to no value after use and are challenging to recycle cost efficiently. In a bid to combat this issue and foster circular economy, the European Union has declared a series of directives to gradually phase out SUPs as a strategy to eliminate these disposables from the market. This approach allows the market time to discover alternative solutions to replace SUPs, promoting the adoption of reusable products. To make a sustainable system of reusable products feasible and profitable, the key lies in devising a business model designed for a circular strategy of repeated use of goods. One effective approach involves establishing a closed-loop supply chain (CLSC) which entails the entire life cycle of a product, from sourcing raw materials, through manufacturing, utilisation, collection, reverse logistics and recycling. The purpose of this study was to develop a CLSC system for reusable plastic products between a plastic producing small or medium sized enterprise (SME) and an incumbent firm customer to attain a smooth transition from linear to circular economy. Employing an inductive approach, this case study considered the EU-directives as observational data, the change of business model as the result, and a general recommendation as the rule. The research method encompassed conducted interviews, mathematical prototyping, product design, and life cycle analysis, using various tools and methods in the process. Two case companies were involved: one large incumbent firm and one plastic producing SME. The aim was to design a circular business model (CBM) to capture the value of the collaboration between these two companies. After an analysation of the current situation, the main obstacles to a successful transition were identified. A comprehensive solution was developed, including a network of partners for the CLSC, a reusable product design, and the necessary implementation calculations. The finalised business model was anchored in the principles of the CLSC, the product design specifications and the calculations that determined the system’s viability. Implementation of the CBM would yield economic advantages for both stakeholders, as well as an improved green image factor and advancement in circular economy. Furthermore, this transition would cultivate valuable and lasting business relationships for both companies. These case findings harmonise with established theories which emphasise the significance of business models that are dependent on collaboration and long-term strategic planning. Lastly, they also underscore that value is created in product utilisation and not ownership.