Internal IT systems enable manufacturers to transition to a circular economy. These systems support real-time monitoring, product ecodesign, waste management, and green procurement. Effective supply chain management tracks, assesses, and processes returned items, transforming reverse logistics into a strategic asset. Evolved CRM systems foster sustainable dialogues with customers throughout the product lifecycle, promoting responsible consumption and facilitating recycling and returns. Internal IT must support redistribution business models like recommerce, Product-as-a-Service, and sharing economy models, optimizing resource utilization and customer engagement. Modules for repair, refurbishment, and remanufacturing extend product lifecycles, ensuring products remain functional longer. Systems facilitate efficient logistics for product returns and recycling, ensure regulatory compliance, and optimize the use of recycled materials. Waste Management Systems (WMS) should integrate AI to optimize waste sorting and processing. Quality Control Systems (QCS) ensure consistent quality standards for repaired, refurbished, and remanufactured products. Inventory Management Systems (IMS) manage refurbished parts and recycled inputs, supporting circularity and reducing waste. Circular design tools enable the creation of sustainable products with extended lifespans. Lifecycle Assessment (LCA) tools provide comprehensive metrics, emphasizing resource efficiency and regulatory compliance. A strategic overhaul of internal IT systems, leveraging AI, IoT, and predictive analytics, is essential for a thriving circular economy.