Universal bonding end clamps used to assembly photovoltaic (PV) arrays and provide an electrically conductive path (or bond) between PV module frames forming part of the PV arrays and a rail system. The bonding clamp includes a clamp portion and a base portion. The clamp portion includes an electrically conductive body having a mounting structure, at least one electrical bonding member extending from the body, and at least one pressure member extending from the body and a base pressure member extending from the body. The clamp portion may also include one or more spacers to facilitate the alignment of the clamp portion relative to the base portion. The base portion includes an upper wall having a mounting structure, a lower wall having a mounting structure and a side wall between the upper and lower walls. When the clamp portion is positioned relative to base portion for installation, the clamp portion mounting structure is aligned with the base portion mounting structures, and the base pressure member engages the side wall.