A sensing structure for an accelerometer includes a support and a proof mass mounted thereto by flexible legs. The proof mass has moveable electrode fingers perpendicular to the sensing direction and at least four fixed capacitor electrodes, with fixed capacitor electrode fingers perpendicular to the sensing direction. The fixed capacitor electrode fingers interdigitate with the movable electrode fingers and the proof mass is mounted to the support by an anchor on a centre line of the proof mass. The proof mass has an outer frame surrounding the fixed capacitor electrodes and the flexible legs extend laterally inwardly from the proof mass to the anchor. The fixed capacitor electrodes comprise two inner electrodes, one on each side of the proof mass centre line, and two outer electrodes, one on each side of the proof mass centre line.