At times, you might have to give a credit to the client as a courtesy or for any other reason. This can be done by writing off all or part of the invoice amount. If you sync CORE data with your accounting software, write-off transfers as a credit or discount. 

You can generate a write-off from the Payments screen (main menu > Billing) in CORE. Check CORE Help Center for details on write-off.

Another option is to give a project credit to the client using the Credit Memos feature. You can create a credit memo for a project, post it to the relevant account and later pay this liability to the client. Check CORE Help Center for details on creating a credit memo.