Let us say you billed a client, received a payment by check, and on depositing it, the payment was declined because of non-sufficient funds (NSF).
In this case, you can go to the Payments screen and select that payment on the grid. Click its row action menu to select Bounced Check. You can enter the bounced check details in the dialog. CORE creates a (negative) NSF payment to undo the payment and then creates a 'bounced check' fee invoice for the amount you specify as an inconvenience charge. Check CORE Help Center for details.
You are now ready to receive a new payment from the client or re-send the invoice to the client.