I have found the 'System' has made payments against invoices that are not real, why and how do i find other errors, and stop it happening?

QuickBooks Online International does not have a native feature that automatically applies payments to open invoices.  Are you perhaps currently using any third-party payment management apps or merchant processors synced with your account? There are many external applications that automatically generate payment transactions in whenever a customer pays you through an outside portal or platform.

If you're not using one, I recommend reaching out to our Live Support team right away. They can investigate what's causing this behavior and help you prevent it from happening again.

To check for any other transactions created by the system, you can select System Administration from the User dropdown menu in the Audit Log.

In the meantime, you can open any payments you have verified as incorrect and manually delete them. This will restore the proper balance due on your client's invoices. Here's how:

1. Open each incorrect invoice and click the payment link located under the Invoice total.
2. On the Receive Payment page, click the More option at the bottom.
3. Select Delete.

Should you have any other concerns, please let us know in the comments.