What is flexi-schooling?

Flexi-schooling describes an arrangement between the parent and the school, in which the child is registered at the school but attends it part-time. The rest of the time, the child is educated at home.
This can be a long-term arrangement or a short-term measure for a particular reason.
To arrange flexi-schooling, the parent needs to make a proposal to the headteacher. It is the headteacher who decides whether to allow the arrangement.
In coming to a decision, the headteacher would normally consult the school’s senior staff, the governors and the local authority, though this is not mandatory."

http://www.usethekey.org.uk/pupils-and-parents/behaviour-and-attendance/attendance/flexi-schooling

"Many schools are unaware that flexi-schooling is an option. They often don't hear about it unless parents request it, and are then hesitant to agree. One common misconception is that local authorities will disapprove, although they have no power to decide – it is the head teacher's decision. There can be concern that the school's global absence scores will suffer, but if the child is registered as "educated offsite" rather than absent, for home-based sessions, this will not be an issue. Another worry is the absence of flexi-pupils during SATs, although parents normally agree to suspend the part-time arrangement while they are on, letting children sit them. In most cases, though, schools are doubtful simply because the arrangement is unusual and outside most teachers' experience." (ref: The Independant 2010)