Thank you for joining the thread, @KAJH.

Allow me to help you clear things out. Know that paying an invoice with zero balance will result in an overpayment.

We'll need to delete your bad debt this will not affect your book from 2021 if you never reconcile it. However, if you've reconciled the bad debt, we'll need to unreconcile the transaction and then delete it.

Once done, the invoice of that transaction will open again and you can now Receive payment.

Here's how:

1. Click the + New icon. 
2. Below the Customer column select Receive payment.
3. In the Customer field dropdown select the customer who incurred the bad debt.
4. Ensure that the Payment method dropdown is a Credit card.
5. Below the Oustanding transaction, tap the box beside the invoice.
6. Hit Save and Close.

Once done, you can reconcile it again manually.

You can read through this article if your want to learn how you can view, print, or export your reconciliation report.

If you have additional queries about invoices or any related concerns, never hesitate to reply to this post. Have a good one!