This paper characterises the properties of unsymmetric bistable carbon fibre composites actuated using a single piezoelectric macro fibre actuator. A piezoelectric–laminate combination under two-axis constraint was evaluated in terms of its load–deflection characteristics, snap-through force and stiffness. The load–deflection characteristics indicate that snap-through force and laminate stiffness increase as a function of piezoelectric actuator drive-voltage. Both snap-through force and laminate stiffness are significantly increased under two-axis constraint, as compared to single-axis constraint. Snap-through force and stiffness are shown to be affected by localised curvature variation caused by laminate ageing.