Classical solid mechanics allows accurate prediction of material behaviour under complex loading conditions in both elastic and plastic regimes. In certain situations, however, it becomes insufficient, leading to discrepancies between numerical predictions and experimental observations. This is particularly evident for materials whose macroscopic response is significantly affected by structural effects at the specimen level, as well as strain-gradient effects at the microscale. An additional limitation of classical continuum theory, resulting from the local nature of differential equations, is the difficulty in describing the initiation and evolution of discontinuities within the material. Due to its integral–differential formulation, peridynamics enables a natural treatment of discontinuities. Nevertheless, the question arises as to whether peridynamics alone is capable of correctly capturing the influence of material structure on the mechanical response, since the horizon radius, often interpreted as a characteristic length, simultaneously acts as a numerical parameter. This motivates the introduction of an additional constitutive parameter with a clear physical meaning. In this work, an implementation of a model based on a simplified Cosserat theory is presented, using the correspondence approach within the non-ordinary state-based peridynamics framework. The model is validated using selected benchmark problems involving a plate under plane stress conditions. The analysis considers different values of the material characteristic length, and the obtained results are compared with finite element solutions. The results reveal a pronounced influence of couple stresses on the force stress tensor and the resulting deformation field. In the case of a plate with a hole, a stress regularization effect is observed in region of stress concentration, becoming more pronounced for larger values of the characteristic length. These findings confirm the relevance of introducing an additional material parameter to account for scale effects and provide a foundation for further model development toward elastoplasticity with damage.