QuickBooks Online Sync Error: You must specify a different number. This number has already been used.
Why the Sync Error occurs
This error occurs when the reference number (Ref#) on a Bill.com offline payment is already in use within QuickBooks Online or has been entered on a payment that is for more than one invoice.
How to Fix the Sync Error
- Click the payment confirmation number from the sync status page
- Click the edit icon
- Enter a unique Ref # not in use in QuickBooks Online
- If paying multiple bills with one offline payment, remove the Ref # completely
- Click Save
- Sync again
Alternatively, record the payment manually in QuickBooks Online and contact Customer Support to request to clear the sync error.