Staging Date
The Staging Date is based on the size of the employer in terms of PAYE scheme size as of 1st April 2012. It is best not to guess when this might be. By entering the Company’s PAYE reference number to The Pension Regulator’s (TPR) website, the correct date can be found.
http://www.thepensionsregulator.gov.uk/employers/tools/staging-date.aspx
Companies with more than one PAYE reference are required to use the Staging date for the earliest Stager and bring forward the others. If you are unsure, make direct contact with the Regulator for their view on your situation.