Abstract: The use of externally bonded fiber reinforced polymer (FRP) laminates for the flexural strengthening of concrete structures is a technique that has become very popular. The effectiveness of this technique hinges heavily on the performance of the bond between the strengthening plate and the substrate, which has been the subject of many existing studies. In particular, the interfacial shear stress between a beam and a soffit plate has been addressed by numerous analytical investigations. Surprisingly, few of these investigations has examined the interfacial shear stress for beams under asymmetrical loads. This paper presents an explicit solution for interfacial shear stress in a simply supported beam bonded with a thin plate using minimum excess principle. The beam can be subjected to a uniform distributed load and unequal moments at both ends. The analytical solution is verified by comparing its predictions with those available in the literature.