Within the Temkin-type approach for two-step mechanisms, the problem of the rate-determining step (rds) and its possible shift on a nonuniform surface is reexamined. The nonuniformity concept is extended to its maximum limits and a new transfer rule is derived for the model’s intrinsic linear free energy relationships. For any thermodynamically allowable coupling of the two steps, this provides a quantitative estimation of rds shift, which is unimportant for reasonable model parameters. The proposed transfer rule leads to a unique analytical solution for the local turnover rate, whatever the steps’ coupling. i