  Black holes (BHs) in an inspiraling compact binary system absorb the
gravitational-wave (GW) energy and angular-momentum fluxes across their event
horizons and this leads to the secular change in their masses and spins during
the inspiral phase. The goal of this paper is to present ready-to-use, 3.5
post-Newtonian (PN) template families for spinning, non-precessing, binary BH
inspirals in quasicircular orbits, including the 2.5PN and 3.5PN horizon flux
contributions as well as the correction due to the secular change in the BH
masses and spins through 3.5PN order, respectively, in phase. We show that, for
binary BHs observable by Advanced LIGO with high mass ratio (larger than ~10)
and large aligned-spins (larger than ~0.7), the mismatch between the
frequency-domain template with and without the horizon-flux contribution is
typically above the 3% mark. For (supermassive) binary BHs observed by LISA,
even a moderate mass-ratios and spins can produce a similar level of the
mismatch. Meanwhile, the mismatch due to the secular time variations of the BH
masses and spins is well below the 1% mark in both cases, hence this is truly
negligible. We also point out that neglecting the cubic-in-spin, point-particle
phase term at 3.5PN order would deteriorate the effect of BH absorption in the
template.
