The possibility of detecting double flavor violating (DFV) top quark transitions at future colliders is explored in a model-independent manner using the effective Lagrangian approach through the t → uiτμ (ui = u, c) decays. A Yukawa sector that contemplates SUL(2) × UY(1) invariants of up to dimension 6 is proposed and used to derive the most general flavor violating and CP violating qiqjH and liljH vertices of renormalizable type. Low-energy data, on high-precision measurements, and experimental limits are used to constrain the tuiH and Hτμ vertices and then used to predict the branching ratios for the t → uiτμ decays. It is found that these branching ratios may be of the order of 10−4–10−5, for a relative light Higgs boson with mass lower than 2mW, which could be more important than those typical values found in theories beyond the standard model for the rare top quark decays t → uiViVj (Vi = W, Z, γ, g) or t → uil+l−. LHC experiments, by using a total integrated luminosity of 3000 fb-1 of data, will be able to rule out, at 95% C.L., DFV top quark decays up to a Higgs mass of 155 GeV/c2 or discover such a process up to a Higgs mass of 147 GeV/c2.