This presentation outlines a practical, step-by-step approach to establishing a monitoring system for article processing charges (APCs), based on the speaker’s multi-year experience at a university level. Rather than presenting data or charts, the talk focuses on methods and tools to track real—not estimated—APC expenditures. The speaker first describes the initial challenges, including inconsistent payment practices, lack of metadata, and absence of APC-specific accounting categories. Through a ten-step guide, the talk illustrates how to implement targeted improvements: integrating APC payment requests within the institutional repository, creating dedicated accounting codes, and ensuring communication and cooperation among researchers, accountants, IT developers, and administrative offices. A key element is the automation and interoperability between the repository and the accounting system, allowing for effective linkage between costs and related publications. The final steps cover how to clean, enrich, and report data, with suggestions for stakeholder-oriented reporting and data sharing with initiatives like OpenAPC. The talk concludes with the message that APC monitoring is a continuous, iterative process—one that demands persistence, collaboration, and a good set of tools.