Numerical and experimental study is performed to evaluate the reactant bypass flow in a catalytic plate reactor with a coated wire mesh catalyst for steam reforming of methane for hydrogen generation. Bypass of unconverted methane is evaluated under different wire mesh catalyst width to reactor duct width ratios, the results show that altering this ratio from 0.98 to 0.96 results in an increase in bypass mass flow of 22%. Effect of catalytic wire mesh flow resistance on bypass flow has also been investigated and results show increased bypass flow as catalytic wire mesh flow resistance increases. The numerical results are in good agreement with experimental data. The study improves the understanding of the underlying transport phenomena in these reactors and shows that the flow maldistribution in a catalytic plate reactor using a coated wire mesh has to be considered.