Variation of shareholders' rights requires class consent or class meeting resolution; minority shareholders can seek tribunal cancellation. Variation of class rights requires written consent of three quarters of the issued shares of that class or a special resolution at a separate class meeting, subject to the memorandum or articles or terms of issue; if one class's variation affects another class, three quarters of the affected class must also consent. Holders of a minority who did not consent or vote for the variation may apply promptly to the Tribunal to cancel it, the Tribunal's decision is binding, and the company must file the Tribunal's order with the Registrar within the statutory filing period.