The alternating current potential drop technique is a nondestructive testing method that is mostly applied to estimate the depth of surface breaking flaws (e.g., cracks) in metallic conductors. When the flaw is hidden (internal or bottom cracks), other techniques (e.g., radiographic) must be used, which may only provide limited information on the location and dimensions of the hidden flaw. This work presents a detailed numerical analysis of ac flow in internally flawed conductors. The results can be used to reveal and estimate the dimensions and location of hidden flaws.