Thanks for the replies. I'm hoping that they will agree to backdate it. Can't work out at the moment if it's a genuine oversight on their part or whether they just thought I wouldn't notice! My post was only for 1 year so need to get the ball rolling before I leave. Wish me luck!
I've been working 2 days per week in a primary school since September. I'd started teaching again after a few years away from it so perhaps wasn't as 'on the ball' as I should have been, and didn't realise I'm entitled to PPA until I had a conversation with someone in a similar role a few weeks ago. This other person has had a 10% PPA allowance payed throughout the year instead of allocated PPA time. Can I ask for similar and ask for it to be backdated to last September? Would the school legally be able to refuse?