I mistakenly marked an invoice PAID. How can i remove that status and send the new UNPAID invoice to the client.

Since marking the invoices as Paid in QuickBooks Self-Employed is solely for tracking purposes, we can easily revert them to unpaid status without any issues, CFPLLC1.

Here's how we can do it:

1. Go to Invoices on the left menu.
2. Look for the invoice you want to unpaid.
3. Click the drop-down arrow next to the View button.
4. Select Mark as unpaid.

If you're planning to receive payments directly from the sent invoices, we can Activate payments. You can check out Turn on payments section of this article to know more about the function: Create invoices in QuickBooks Self-Employed.
 

When the payments are cleared from your bank, they will now flow to your Transactions page and categorize them properly.

Keep us posted if you need additional help in managing your invoices. We'll be around to give you a hand.