This is HIGHLY dangerous because you are messing with money and changing historical financial records. But… you can do it for situations where transactions were recorded in error. Please document everything for auditors and/or accountants.
How to turn this feature on:
There is a Configure | User Access function called “Edit Invoice Amounts”. This triggers the ability to edit offline transaction records such as Cash, Check, Credits, or any custom payment types. The one transaction ASAP guards incredibly tightly are credit card transactions run through ASAP. These you cannot edit because they are tied to a merchant account. If you do not have access to these settings, you'll need to contact an administrator within your organization that does have the user access rights to make these changes. Our ASAP staff cannot change user access settings for you.