Reaction mechanisms for the acidic dissociation of HCl in water clusters are considered. Intermediates in the reaction are obtained from stationary points on the potential energy surface of the systems HCl-(H2O)(n) with n=4 and 5. These points have been determined by the B3LYP density functional method in an aug-cc-pVDZ atomic orbital (AO) basis. The total energies of the stationary points are checked by the coupled cluster single-double-triple [CCSD(T)] method in the same AO basis. For the case of n=4 a multibody analysis of the interaction energies is performed by the CCSD(T) method as well as by symmetry adapted perturbation theory. The clusters have a completely dissociated form as their energetically lowest minimum.