  The aim of the paper is twofold. Firstly, we would like to derive
quantitative uniqueness estimates for solutions of the general complex
conductivity equation. It is still unknown whether the \emph{strong} unique
continuation property holds for such equations. Nonetheless, in this paper, we
show that the unique continuation property in the form of three-ball
inequalities is satisfied for the complex conductivity equation under only
Lipschitz assumption on the leading coefficients. The derivation of such
estimates relies on a delicate Carleman estimate. Secondly, we study the
problem of estimating the size of an inclusion embedded inside of a conductive
body with anisotropic complex admittivity by one boundary measurement. The
study of such inverse problem is motivated by practical problems.
