As a maintained school all admissions are administered by the Local Authority. A link to their page can be found here http://www.buckscc.gov.uk/education/schools/admissions-and-moving-school/
We admit children from the September after their 4th birthday. Applications for a school place for these 'Rising 5's' are completed online in the previous January. Priority for places is given to children within the school's catchment. Butlers Court catchment can be seen here https://services.buckscc.gov.uk/school-admissions/schools/110291 Siblings of children already attending Butlers Court are given next priority and then places are allocated on distance from the school.
In year admissions for other ages are possible when a place becomes available. Infant class size regulations limits classes to a maximum of 30 children. In year admission applications are made to the Local Authority and when a place becomes available the above criteria is applied to allocate the place.