The aim of this study is to develop a numerical procedure to simulate the flexural behaviour of carbon fibre-reinforced plastic-strengthened timber beams. Since wood exhibits complex failure modes, its behaviour can only be captured through the use of multidimensional failure criteria, a local approach based on the coupling of orthotropic elasticity and anisotropic plasticity described with the quadratic criterion of Hill is presented to model this behaviour. The theoretical and numerical aspects of the constitutive equations are presented in detail. The resolution of the resulting system of equations is carried out via a VUMAT user material, using ABAQUS/Explicit finite element code. The obtained results show that the proposed formulation can efficiently capture the global response with acceptable accuracy.