Would this be paid for by yourself or do you qualify for the government funded Extended Childcare Offer (ECO)?
ECO eligibility: You, and any partner, must each expect to earn (on average) at least £152 per week (equal to 16 hours at the National Minimum or Living Wage). You can't get 30 hours free childcare if either you, or your partner, each individually expect to earn £100,000 or more.