Purpose - The purpose of this paper is to investigate the effect of geometric variables on the stress and strain distributions, as well as non-linear deformation behaviour of aluminium alloy 2024-T3 single-lap bolted joints loaded in tension. Design/methodology/approach - The study has been conducted by using numerical and experimental approaches. In the numerical part, 3D FE models were generated using ANSYS software for different e/d and W/d ratios in which e and W are variables but the hole diameter (d) is constant. Stress and displacement results for each case have been discussed to better explain the mode of failure. In the experimental part, e/d=3 and W/d=6 ratios were selected as constant and testing specimens were produced accordingly. The aim was to obtain baseline experimental load-strain and load-displacement values for selected specimen geometry coordinated with the numerical analyses. Findings - The good agreement between the experimental and numerical analysis provided confidence in the numerical methodology used to evaluate the different geometric variables. The results showed that the single-lap bolted plates with optimised W/d and e/d ratios could shift the failure mode from net-tension and shear-out to bearing failure by directing the maximum damaging stresses from the stress concentration region and shear-out planes towards the bearing region, leading to higher failure loads. Originality/value - The paper develops a FE model of single-lap bolted joints with a non-linear material model and investigates 3D stress analysis as well as non-linear deformation behaviour of bolted plates; optimisation of plates' width (W) and edge distance (e) to control failure modes; and bigger W/d and e/d ratios shift net-tension and shear-out to bearing failure mode.