How do I un mark an invoice as paid in full

Welcome to the Community space, @pboutin21.  

The option to change the status of the paid invoice to unpaid is unavailable in QuickBooks Self-Employed. Alternatively, we can delete the transaction and recreate it.

Here's how you can delete an invoice:
 

1. Navigate to the left-hand menu, then select Invoice.
2. Locate the specific invoice transaction we'll delete.
3. Under the Action column, click the dropdown icon, then choose Delete.

Additionally, I'm attaching these references  to help you manage your transactions:

• Categorize transactions in QuickBooks Self-Employed
• Manually add transactions in QuickBooks Self-Employed
• Add older transactions to QuickBooks Self-Employed

If you have more queries about your invoice transactions, don't hesitate to reply to this post. We'll reply to you as soon as possible.