The strong field dissociation of HCl+ at a wavelength of λ = 10.3 µm is examined in detail, using quantum wavepacket and trajectory methods. Athree-potential-curve treatment, which currently offers the most theoretically completedescription of the molecular dynamics, is used to simulate the dissociation process, and providespredictions of the dissociation probability, electronic branching ratios and kinetic energydistributions. Classical trajectory simulations on a single potential curve (ground state ofHCl+)are used to increase understanding of simulations performed using three potential curves.The impact on predicted product properties of using two potential curves (ground and firstexcited states) versus three potential curves is also explored. The fragment’s kinetic energydistributions are discussed extensively and quantum simulation results interpreted with theaid of classical trajectories as well as simple models such as a wagging potential tailmodel, developed by Thachuk and Wardlaw (1995 J. Chem. Phys. 102 7462). Atunnelling variant of a barrier suppression model, used for predicting the dissociationthreshold, is developed, and shown to be more accurate than previous models.