Homelessness remains a critical social issue in Ireland, yet its true scale is systematically obscured by definitional limitations, methodological inconsistencies, and political interference in data collection. While official statistics reported 16,058 individuals relying on emergency accommodation as of July 2025 (a rise of +244% since July 2015), this figure excludes substantial populations: rough sleepers, domestic violence survivors, asylum seekers, and those experiencing hidden homelessness through enforced parental co-residence. This article examines the politics of homelessness enumeration through a critical analysis of seven data sources, policy documents spanning 2014–2025 and stakeholder interviews. The study reveals how Ireland’s measurement system exemplifies the political life of numbers. The analysis exposes five interconnected dimensions of measurement failure: fragmentation of sources and measurement approaches, methodological inconsistencies that undermine longitudinal analysis, systematic undercounting that renders substantial populations invisible, documented political manipulation and data integrity concerns, and structural barriers that impede comprehensive data collection and analysis. The findings demonstrate how apparently technical decisions about data collection and analysis become sites of political contestation. The research reveals the measurement politics in contemporary welfare states, demonstrating the need for inclusive frameworks, integrated systems, and transparent practices that prioritize social justice over administrative convenience.