  We discuss some general properties of the symmetry-resolved von-Neumann
entanglement entropy in systems with particle number conservation and describe
how to obtain the entanglement components from correlation functions for
Gaussian systems. We introduce majorization as an important tool to derive
entanglement bounds. As an application, we derive lower bounds both for the
number and the configurational entropy for chiral and Cn-symmetric topological
phases. In some cases, our considerations also lead to an improvement of the
previously known lower bounds for the entanglement entropy in such systems.
