Are you referring to credits automatically applied to your invoice? We can turn off this feature if you don't want to include it when creating an invoice.
Here's how:
Click the Gear icon on the top menu.
Choose Accounts and Settings.
Select Advanced.
Tick the Pencil icon in the Automation section and uncheck the option for Automatically apply credits.
If you're referring to Account Summary showing on your invoice, you have the option to disable it. Just go to your invoice template to remove the summary on the form.
Here's how:
Click the Gear icon on the top menu.
Choose Custom Form Styles.
Hit Edit on the invoice template under the Action section.
Tick Content and select the Table part on the sample invoice.
Uncheck the Show on invoice field under Account Summary.
Tap Done.
I have articles here about account summary and customizing templates: