Childcare Grant

Hi, I have approved my childcare provider's invoices as they go back to September. Are they able to submit future invoices or can you only submit invoices for weeks commencing in the past? For example, my monthly November invoice is due on November 30th when the nursery expects payment in full. Otherwise, they'll add on hefty daily late payment charges. Can they only submit the weekly invoice on November 30th or can then do this in advance?

Many thanks