Credit Invoice already generated

[corarene]

hello I am trying to figure out how to credit a invoice.

Here is the scenario: My company failed to meet a service agreement which results in a credit to the customer. The customer want to apply the credit to their current bill and the pay the remaining. How do I take this credit and apply to bill with notes that this was from a credit.

[netshine]

If it is for an existing invoice, just edit the invoice and add a new line item with a negative amount.