Quickbooks Online Sync Error: Fund Transfer XXXXXX cannot be created in QuickBooks Online

Quickbooks Online sync error 'Fund Transfer XXXXXX cannot be created in QuickBooks Online';Reason: Duplicate Document Number Error : You must specify a different number. This number has already been used. DocNumber=X is assigned to TxnType=Journal Entry with TxnId=XXXX

Why the sync error occurs:

This error occurs because the Funds Transfer journal entry for Bill.com payments has a duplicate journal number and cannot sync to Quickbooks Online.

How to fix the sync error:

  1. In Quickbooks Online, select the QuickBooks Gear icon
  2. Under Your Company, select Accounting & Settings
  3. Select the Advanced tab
  4. Select the Other Preferences section
  5. Select the Warn if duplicate journal number is used box
  6. Select Save
  7. Select Done
  8. Sync again