This forum is to discuss different features/issues of Oracle Financials modules ( GL - General Ledger, AP - Accounts Payable, AR - Accounts Receivable, FA - Fixed Assets & CM - Cash Management ).
To pay partial amount in single invoice you need to go to payments workbench and then make the payment by selecting the amount for the invoice in "Enter/Adjust invoices".
Or you can split the payment schedule in invoice window & can continue with the payment.