Setting, or applying, a credit means using an available credit to lower the balance of a transaction such as an invoice or a bill. (Creating a credit, on the other hand, means making a credit available to be applied in the future.)
Notice that if you use a credit (SetCredit) only, in your ReceivePayment or BillPaymentCreditCard Add request, then no transaction ID is created, because, from the viewpoint of QuickBooks, there was no transaction. Setting a credit merely creates links between existing transactions (for example, between a credit memo transaction and an invoice transaction), and no information about these links will be returned to you in the response.
If you need to retrieve which transactions were linked in the SetCredit, for Bill Payment, you must do a BillQuery and specify IncludeLinkedTxns. For more information, including information on breaking the links (voiding the credit payment), see the QuickBooks SDK Programmer’s Guide chapter on Receiving payments, bill payments, and deposits.
| FIELD NAME | QUERYABLE | UPDATEABLE | REQUIRED ON UPDATE | INSERTABLE | REQUIRED ON INSERT |
| CreditTxnID | false | false | true | true | true |
| AppliedAmount | false | false | true | false | true |
| Override | false | false | true | false | true |
| PARENT_IDKEY | false | true | true | true |
CreditTxnID: The ID of the credit memo that you are applying to this invoice or bill.
AppliedAmount: Amount of a credit that is applied to a customer’s invoice, or amount of a payment that is applied to a particular bill or vendor credit.
