A vehicular accessory retention clip is used to attach a vehicular accessory, such as vehicular trim, to a vehicle. The vehicular accessory may have a substrate component that has at least one reinforcement post, and the vehicle may have a vehicular base component that has at least one corresponding opening configured to receive the reinforcement post. The retention clip has at least two walls that extend from an edge of a platform, each wall having an exterior tab and an interior tab configured to engage with the walls of the opening and the reinforcement post, respectively. The retention clip is slid onto the reinforcement post until the interior tabs engage with the reinforcement post, and the combination of the retention clip and reinforcement post is inserted until the exterior tabs engage with the walls of the opening.