Abstract Urban infrastructure financing is a critical determinant of sustainable service delivery in rapidly urbanising cities. This study examines the effectiveness of existing financing models in delivering infrastructure services that are available, affordable, and accessible to residents of the Abuja Municipal Area Council (AMAC), Federal Capital Territory (FCT), Nigeria. Anchored on the Finance–Mediators–Outcome (FMO) framework and guided by Sustainable Development Goal 11, the study employed a mixed-methods approach, integrating quantitative data from 384 household surveys with qualitative insights from semi-structured interviews of policymakers and community representatives. Findings reveal a diversified financing landscape, including government funding, private sector investment, Public–Private Partnerships (PPPs), and community-based arrangements. Electricity and water supply services recorded higher availability, while housing and waste management exhibited significant service gaps. Affordability and accessibility challenges persist, particularly for low-income and peri-urban populations. The study concludes that although current financing mechanisms have enhanced resource mobilisation, they do not automatically guarantee equitable and sustainable service delivery. Recommendations include strengthening PPPs with equity safeguards, improving institutional coordination, enhancing transparency, and supporting community-based initiatives to bridge service gaps. The study contributes empirical evidence on the relationship between financing models and urban infrastructure outcomes, providing actionable insights for policymakers, urban planners, and development stakeholders in the FCT.