The paper is focusing on the analysis of structural behaviour of thin-walled cold-formed steel (TWCFS) members with lipped channel cross-section under eccentric compression (around minor and major axes), especially on the upper bound limit estimation based on plastic mechanisms analysis. This analysis deals with obtaining upper bound estimation of ultimate strength on the basis of analytical-numerical methods: finite difference method (FDM), yield line analysis (YLA). Experimental tests were conducted to obtain data base used in YLA and to model plastic mechanism geometry. EN 1993-1-3 standard was used as alternative to obtain failure curves. Taking into account failure curves and pre- and post-buckling paths of equilibrium, UPB estimation is able to make. This approach can be used in pushover analysis to specify behaviour of structure. Conclusions regarding the potential application of upper bound ultimate strength estimation using the YLA approach are drawn, along with discussions on the challenges of implementation and suggestions for future research in this area.