This study investigates how municipal cash transfer programmes influence intra-urban inequality through the case of Maricá, Brazil. Using over 3.4 million transactions from a local digital currency, we trace the spatial flow of social benefits and assess economic spillovers via local multiplier (LM3) and urban scaling models. Despite a strong multiplier effect, spending is highly concentrated in a few retailers (Gini = 0.80), while neighbourhood-level business revenue scales superlinearly with social benefits (β = 1.15). These findings reveal how redistributive policies interact with spatial inequalities, offering new insights into the geography of welfare and the design of inclusive urban policy.