The redistribution of solute during phase transformations where solute partitioning occurs at the two‐phase interface has been mathematically treated for (i) the special case of equal diffusion rate in both the liquid and solid and (ii) diffusion only in the liquid under the additional force of a constant electric field. This one‐dimensional analysis shows that (i) diffusion in the solid has a small effect on the grown‐in solute distribution fork0<1 but an appreciable effect fork0>1 and (ii) the presence of an electric field can significantly alter the grown‐in solute distribution. Further, one can deduce from the latter analysis a new experimental method for determining the effective ionic mobility of the solute species in the liquid phase.