  We consider three dimensional $N=4$ flat supergravity, with an abelian
R-symmetry enhancing the gravitational phase space. We obtain the field
configuration whose asymptotic symmetries at null infinity coincide with the
centrally extended $N=4$ super Bondi-Metzner-Sachs (BMS) algebra .The killing
spinors for this generic configuration are obtained together with the energy
bounds imposed by supersymmetry. It is explicitly shown that the same algebra
can be obtained as a flat (AdS radius $\rightarrow \infty$ ) limit of the
combined $(2,0)$ and $(0,2)$ sectors of AdS supergravity.
