The invention relates to a panel and a locking system (1) for panels (2, 3) with edge profiles provided on at least two opposite edges of the panels (2, 3) for the positive connection of similar panels (2, 3), including an edge profile designed as a groove profile (4), with an upper groove wall (6) and a lower groove wall (7), and an edge profile designed as a tongue profile (5), with a notch projection (12) on the underside of the tongue that engages a notch recess (11) in the lower groove wall (7) of an adjacent panel in the assembled state, where the engaged edge profiles form an articulated joint (G) that acts to restore the panels (2, 3) to their installation plane when deflected either up or down, where the upper groove wall (6) has a flank (21) on the inside that opens towards the free end of the groove wall (6).