Abstract. In this paper we show that the effect of the saddle currents in the rigid sectors slows down the vertical instability of JET elongated plasmas by a factor of about two with respect to estimates based on pure axisymmetric models. This significantly improves the agreement between the theoretical predictions and the experimental results. The CREATE-L model taking into account the 3D effects of the eddy currents has been applied to various JET pulses; the growth rates have been estimated within an accuracy of 5% for plasmas with a growth time longer than 2ms. This model can be used for JET and extended to ITER-FEAT to provide a reliable test bed for assessing the performance of the vertical control system, and give an estimate of the loads on the structures during VDEs and plasma disruptions.