Yes but you will miss the offered discount for a single payment which is ( £220 for first child, £200 for second and £180 for any additional child ).
Paying by installment is only available under specific circumstances which the school might consider under the following conditions:

• Paying by Installments is available only for families that have more than one child.
• The first installment for each child would be £140 payable on the day of enrollment.
• The second installment due on the first day of school in January as follows:
  • First child £100
  • Second child £80
  • Each additional child £60
• Failure to make payment on time may lead to the child to be excluded from school.