Short answer: the headteacher is accountable; someone senior owns it day to day; governors scrutinise. AI doesn't need a novel accountability structure — it slots into the pattern schools already use for safeguarding and data protection.
The structure that works
In most primary schools: the headteacher holds overall accountability, a deputy head or the DSL owns the policy and staff guidance day to day, the DPO advises on anything data-related, and the governing board receives a short AI update at least termly through an existing committee. No new committee is needed — a standing agenda item is enough. Our governance framework guide and governor briefing set out each role.
The mistake to avoid
The failure mode is diffuse ownership — "we all keep an eye on it" — which in practice means nobody does. Name one senior owner, put AI on one committee's agenda, and the structure holds. Leave it ownerless and the first you'll hear of a problem is after it's happened.