  We revisit electroweak radiative corrections to Standard Model Effective
Field Theory (SMEFT) operators which are relevant for the $B$-meson
semileptonic decays. The one-loop matching formulae onto the low-energy
effective field theory are provided without imposing any flavor symmetry. The
on-shell conditions are applied especially in dealing with quark-flavor
mixings. Also, the gauge independence is shown explicitly in the $R_\xi$ gauge.
