You can apply a posted prepayment.
You must select the Allow Adjustments In Payment Batch option on the A/P Options screen if you plan to adjust the invoice or debit note you are paying.
To apply a prepayment or credit note to an invoice or a debit note:
If you know the numbers of the documents to which you are applying the invoice, or there is a large number of documents for this vendor, select the Filter Documents option. Otherwise, clear this option.
If you are using Filter Documents:
Note: You can enter a discount taken that exceeds the discount specified on the original invoice.
If you are not using select mode:
If you need to adjust a document you are paying:
The A/P Miscellaneous Adjustment Entry screen appears.
Note: This button is available only if the Allow Adjustments In Payment Batch option is selected on the A/P Options screen.
Note: You must print batch listings before posting if you select the Force Listing Of All Batches option on the Processing tab of the A/P Options screen.
Note: If any transactions cannot be posted, Accounts Payable will create a new batch containing the transactions with errors.