How to Apply A Journal Entry Credit To An Invoice
Have you created a journal entry to credit a customer, and need to apply it to the invoice? To use the following solution: 
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You must have made a journal entry using Accounts Receivable as the associated account You must have selected the customer's name from the drop-down menu. 1. Choose Customers > Receive Payment. 2. Select the customer name. 3. Make no entry on the form. Beneath the form, make sure the journal entry credit and the invoice(s) it will apply to are checked off at the left. If you don't see a credit listed, make sure that the two requirements listed above are met. 4. At the bottom, click Save and new or Save and close.