When you are in the Apply/Unapply Prepayments window you can narrow your search for prepayments to apply by using the Find Prepayments to Apply window.
To use the Find Prepayments to Apply window:
In the Apply/Unapply Prepayments window, choose Find from the View menu. Payables opens the Find Prepayments to Apply window.
Enter any search criteria to narrow your search:
Prepayment Number. Invoice Number of the prepayment.
Prepayment Dates. Range of invoice dates for the prepayment(s).
Supplier Site.
Earliest Settlement Dates. Range of settlement dates.
Prepayment Amounts Available. Range of original invoice amounts for the prepayment(s).
Choose Find to have Payables list in the Apply/Unapply Prepayments window all prepayments that match your search criteria.