In this work a non-local band-to-band tunnelling model has been successfully implemented into a fullband Monte Carlo simulator and applied to Tunnel-FET devices. No stability or statistical noise problems were encountered in spite of particle weights ranging over many orders of magnitude (due to vastly different generation rates at different positions inside the device and biases) so that Tunnel-FET I-V curves could be traced over the whole on-off range. Different approaches for the choice of the tunnelling path have been compared and relevant differences are observed in both the current levels and the spatial distribution of the generated carriers. (C) 2011 Elsevier Ltd. All rights reserved.