Applications must be made online or a CAF1 submitted to SSC admission dept as per guidance by 15th January 2019 at the latest. A SIF should also be submitted to the school. It is a requirement to formally consult on any changes to admission arrangements.
This is the link for the information if you are moving schools at a time other than normal transfer, clicking on the section 'how to apply for a voluntary aided, foundation , free school or academy which advises completion of ADM1 as well as the SIF. https://www.suffolk.gov.uk/children-families-and-learning/schools/school-places/move-to-a-different-school-in-year-applications/