  We compute branching functions of $G/H$ coset models using a BRST invariant
branching function formulae, i.e. a branching function that respects a BRST
invariance of the model. This ensures that only the coset degrees of freedom
will propagate. We consider $G/H$ for rank$(G/H)=0$ models which includes the
Kazama-Suzuki construction, and $G_{k_1}\times G_{k_2}/G_{k_1+k_2}$ models. Our
calculations here confirm in part previous results for those models which have
been obtained under an assumption in a free field approach. We also consider
$G_{k_1}\times H_{k_2}/H_{k_1+k_2}$, where $H$ is a subgroup of $G$, and
$\prod_{a=1}^mG_{k_a}/G_{\sum_{a=1}^nk_a}$, whose branching functions, to our
knowledge, has not been calculated before.
