I have one dd going into yr 1 whoc goes to her CM 2 days/week after school and the same 2 full days in holidays. Our agreement has been that we don't pay CM when she takes holiday (she has no back-up cover) but we pay full amount when we are on holiday.
In the last year, this has meant pay 5 weeks of 2 full days/week that we have not used. I could switch to the out of school club which only charges for days used but I am loathe to do that as dd is very attached to her CM and the other dc there. She has been quite shy and I'm not sure she is ready for the school club just yet.
Would it be reasonable to ahve some other kind of arrangement with CM? Full fees for time not used does seem a lot - or is there no way out of this situation except to stop using CM. It is particularly aggravating as I find my hours come in intensive bursts of 3-4 weeks at a time - so some times I need more chidlcare but would have to pay extra - yet other times I can't use what I've already paid for.