This practice note gives an overview of the employer pension reforms that came into force on 30 June 2012 and will eventually require all UK employers to auto-enrol eligible workers in a pension scheme and make mandatory minimum contributions. The note summarises the key employer pension duties and looks at how implementation of the reforms is being staged over several years. It explains which workers are eligible for auto-enrolment, the right to opt out of a scheme once a jobholder has been auto-enrolled and the right of a worker not eligible for auto-enrolment to opt in. At the 2015 Autumn Statement, the government announced a delay in implementation of the transitional rules for increased mandatory minimum contributions to DC schemes. We will update this note to reflect the new timetable as soon as practicable.