Roll-formed aluminium members fabricated using 5052-H36 aluminium alloy grade have been recently employed as structural members in construction. Their web crippling performance has not been fully investigated, particularly when holes are perforated in the web element. Therefore, this study is performed to study the effect of web perforations on the web crippling strength of aluminium lipped channels (ALC's) under the Interior-Two-Flange (ITF) loading condition. Laboratory tests were performed on ALC's with circular holes located at the mid-depth of the web. Finite element (FE) models were then developed and validated against the experiments. A parametric study was conducted to explore the effect of several influential parameters, including opening diameter, section depth, inside bent radius, bearing length, and aluminium grade, on the web crippling capacity. Based on the acquired data, a detailed assessment of the available design guidelines was undertaken, and reduction factor equations were proposed for the ITF loading condition. The proposed reduction factor can accurately predict the reduction in the web crippling capacity for ALC's under the ITF loading condition with fastened and unfastened flange restraint scenarios.