This article evaluates the effects of a revenue-neutral tax reform introducing a universal basic income scheme coupled with a flat income tax which replaces the existing minimum income benefit, several other conditional benefits and the existing progressive income taxation. To this aim we use a Micro–Macro simulation model for the French economy. Interestingly, our results show that the reform induces not only a significant reduction in income inequalities and poverty, but also a slightly positive effect at the macroeconomic level, implying that the equity-efficiency trade-off would not be produced.