this is from the gingerbread website "Once your child is 3 you can use a combination of universal credit and free childcare schemes to pay for childcare.
If your childcare provider participates in the 30 hours term-time free childcare scheme, you will be able to use that scheme to receive 30 hours of free childcare during term-time. If you need more than 30 hours childcare, you can pay for the other childcare hours by claiming universal credit childcare element payments to cover 85% of the costs, up to a maximum monthly amount of £646.35 for one child and £1108.04 if you have two or more children.
You would then pay for the rest from your own income, e.g. your wages."
does your nursery have a finance person? They'll probably know more