How can I correct my mistake if I marked the wrong invoice paid?

It's great to have you here in the Community, @mobilemower4u.

In QuickBooks Self-Employed (QBSE), marking an invoice as unpaid is not available. No worries. I've got a workaround for you. You can duplicate the invoice and delete the paid one.

Here's how to duplicate the invoice:

1. Select Invoices from the left pane.
2. Locate the invoice.
3. Click the drop-down menu under the Action column.
4. Select Duplicate.
5. Click on Save.

Once you've created the duplicate invoice, it's time to delete the paid one. Here's how:

1. Select Invoices from the left pane.
2. Locate the invoice.
3. Click the drop-down menu under the Action column.
4. Select Delete.

Additionally, you can run a report to get your business' finances. 

If you have any concerns or questions about invoices, don't hesitate to post them here in the Community. We're always here to help you in any way we can.