QuickBooks Online sync error: This bill's already been paid
Why the error occurs
This error occurs when a payment on a bill in Key CashFlow is trying to sync to QuickBooks Online, but the bill is already marked as paid in QuickBooks Online.
How to fix the error
Option 1: Void the payment in QuickBooks Online
The easiest solution to this error is to void the payment in QuickBooks Online and sync again, so the payment in Key CashFlow syncs to QuickBooks Online.
Option 2: Keep the payment in QuickBooks online
If you need to keep the payment you recorded in QuickBooks Online, contact Customer Support to clear the error.