Under the Pensions Act 2008, every employer in the UK must put certain staff into a pension scheme and contribute towards it. This is called 'automatic enrolment'.
The date automatic enrolment comes into force for an employer is referred to as the “Staging date”. This date is determined by the size of the workforce as at 1 April 2012 and can be confirmed using the company’s PAYE reference code using the following tool available via the Pensions Regulator’s website
For companies set up after 1 April 2012, once the first payroll has been run under the companies PAYE reference, HMRC will notify The Pensions Regulator who will then allocate a staging date and inform the company.