A minimum employer contribution is a mandatory pension contribution in the United Kingdom, which was made compulsory by the Pensions Act 2008, however it did not come into force until 2012. As a result, all staff are required to be automatically enrolled in a pension scheme when they join a firm. The Cameron Ministry modified this rule by means of the 2011 Pension Act, which brought the rule into force in a series of tranches of employers, over several years (finishing by the end of 2017), instead of all at one moment.