  We use flat-space holography to calculate the mutual information and the
3-partite information of a two-dimensional BMS-invariant field theory
(BMSFT$_2$). This theory is the putative holographic dual of the
three-dimensional asymptotically flat spacetimes. We find a bound in which
entangling transition occurs for zero and finite temperature BMSFTs. We also
show that the holographic 3-partite information is always non-positive which
indicates that the holographic mutual information is monogamous.
