  We study intrinsic charge-carrier scattering mechanisms and determine their
contribution to the transport properties of the two-dimensional ferromagnet
Fe$_3$GeTe$_2$. We use state-of-the-art first-principles calculations combined
with the model approaches to elucidate the role of the electron-phonon and
electron-magnon interactions in the electronic transport. Our findings show
that the charge carrier scattering in Fe$_3$GeTe$_2$ is dominated by the
electron-phonon interaction, while the role of magnetic excitations is
marginal. At the same time, the magnetic ordering is shown to effect
essentially on the electron-phonon coupling and its temperature dependence.
This leads to a sublinear temperature dependence of the electrical resistivity
near the Curie temperature, which is in line with experimental observations.
The room temperature resistivity is estimated to be $\sim$35 $\mu \Omega
\cdot$cm which may be considered as an intrinsic limit for monolayer
Fe$_3$GeTe$_2$.
