The stability of the panel zone plays a critical role in the performance of steel moment-resisting beam‑to‑column connections. Continuity plates are commonly used to prevent local instability in the column web and flanges; however, existing design provisions are primarily based on studies of wide‑flange sections, and limited information is available regarding the behavior of double‑IPE built‑up columns under concentrated compression. This study investigates the local load‑bearing capacity and instability mechanisms of double‑IPE built‑up column webs subjected to double compression loading. A finite element model is developed to simulate local instability under concentrated load, and its accuracy is validated using available experimental data. Subsequently, the behavior of 15 double‑IPE built‑up column specimens under double compression loading condition is examined. The web and continuity plate capacity predicted by the AISC 360‑22 specification are compared with the finite element analysis results. The findings indicate that the actual web compression buckling capacity ranges from 132% to 189% of the theoretical predictions for columns without continuity plates, while the effective load‑bearing capacity of continuity plates ranges from 91% to 147% of the theoretical values. Finally, suggestions were proposed for determining the capacity of the web and continuity plates in built-up IPE columns.