  We derive the antipodal matching relations used to demonstrate the
equivalence between soft graviton theorems and BMS charge conservation across
spatial infinity. To this end we provide a precise map between Bondi data at
null infinity $\mathscr{I}$ and Beig-Schmidt data at spatial infinity $i^0$ in
a context appropriate to the gravitational scattering problem and celestial
holography. In addition, we explicitly match the various proposals of BMS
charges at $\mathscr{I}$ found in the literature with the conserved charges at
$i^0$.
