The chemical reactions and pathways resulting in the formation of phytic acid, myo-inositol hexakisphosphate, by the successively phosphorylation of myo-inositol or an inositol trisphosphate; the inositol trisphosphates that may be used by this pathway are inositol 3,4,5-trisphosphate and inositol 3,4,6trisphosphate.