Do schools have to provide a reference?
You don't usually have to give a work reference, but if you do write one, it must be fair and accurate.
However, you're required to give a reference if there was a written agreement to do so.
This is explained on the GOV.UK website.
Who can write a reference?
There are no specific rules about this, but it should be someone who knows the individual in question well. They should also be a staff member with appropriate authority.
However, regardless of who writes the reference, all references should go through your headteacher or a nominated member of the senior leadership team (SLT) who can then sign the reference off.
This was explained to us by One Education and the Association of School and College Leaders