Web crippling is a common failure mode in cold formed sections. Interaction between bending and web crippling reduces the load carrying capacity and may control the design. In this research, numerical study on web crippling and interaction between bending and web crippling are performed considering the material and geometric nonlinearities. The study is performed on channel sections subjected to web crippling under interior one flange (IOF) loading conditions. Finite element models are verified against experimental tests, and then extended to predict the web crippling strength of the studied channel sections. FE is used to investigate the interaction between bending and web crippling in C-sections. FE results are employed to investigate the effect of different parameters on sections resistance. It was found that, the strengths predicted by design codes are generally inadequate for channels with a practical web slenderness range. Therefore, modifications were proposed to improve the strength predicted by codes.