Australia NSW Preschool Fee Relief Allocation in MYOB

It is my understanding that the NSW Preschool Fee Relief needs to be shown as a credit against any fees shown on an invoice. My question is: if the childs day fees etc are allocated to an income account in MYOB and on the invoice, but the Fee Relief we receive is also income, how can I allocate the fee relief amount on the invoice? I can't use the Fee Relief income stream, as this would just be increase the amount of the invoice? Thanks