Before I changed my policy I did charge a holding fee over the summer but insisted the child come one day a week or two part days to assure that the child progressed along with the group and the parent liked it because it gave them one day a week to do their own thing and they were paying for it anyways. My main reason was partly so the parent couldn't undo all my rules over the summer but it was more to keep me and the parent and child in contact all summer. It is harder to hide that you are planning to make changes if you see the caregiver and you chat about things including the coming year all summer long.