==Credit Invoice==
*Go to {{#fas:cog}} (SETTINGS->) ACCOUNT->PREFERENCES and set "Close Invoices" = Yes.
*Close the invoice you want to credit.
*Go to "Charges and Payments" and enter negative values for the items you want to credit.
If required you can set up a different invoice template in {{#fas:cog}} (SETTINGS->) GUEST MANAGEMENT->INVOICE. You can select which template is used after you have clicked on "Printable Invoice".
==Cancel Invoice==
*Go to SETTINGS->ACCOUNT->PREFERENCES and set "Lock Invoices" = Yes.