  Two dimensional field theories with Bondi-Metzner-Sachs symmetry have been
proposed as duals to asymptotically flat spacetimes in three dimensions. These
field theories are naturally defined on null surfaces and hence are conformal
cousins of Carrollian theories, where the speed of light goes to zero. In this
paper, we initiate an investigation of anomalies in these field theories.
Specifically, we focus on the BMS equivalent of Weyl invariance and its
breakdown in these field theories and derive an expression for Weyl anomaly.
Considering the transformation of partition functions under this symmetry, we
derive a Carrollian Liouville action different from ones obtained in the
literature earlier.
