<p>The European Union mandate for separate textile waste collection necessitates the development of robust infrastructural and processing frameworks to advance circular economy objectives. Strategic planning for this systemic transition inherently relies on rigorous baseline analyses. To support these analytical demands, current monitoring mechanisms are undergoing systematic refinement through the aggregation of operational data from producers and waste management entities. Although these aggregated datasets are routinely utilized for strategic planning, the fundamental structural integrity of the data, specifically their adherence to basic logical constraints and topological relationships, is rarely subjected to rigorous evaluation. To address this methodological gap, the present study introduces a unified indicator designed to objectively quantify the reporting error rate within waste management monitoring systems. The proposed metric is subsequently validated through a detailed case study focussing on textile waste flows in the Czech Republic. The application of the unified indicator quantifies the overall systemic reporting error at 19.7%. The most significant discrepancies occur during transport, directly impacting the accuracy of final waste treatment reporting. Beyond the diagnostics of reporting fidelity, the underlying material flow analysis demonstrates that 39% of textile waste, equivalent to approximately 29 kilotonnes, underwent recycling in 2022. Ultimately, the mathematical principles and the evaluation framework formulated in this research possess high generalizability, rendering them readily adaptable to any alternative waste fraction.</p> Graphical Abstract <p></p>