Hi james180,
Thanks for posting in the Community!
An error code 6140: Duplicate Document Number error occurs when trying to export the payroll journal to QuickBooks if the current active journal number has already been used.
We can turn off an option on your settings to successfully export your payroll journals to QuickBooks. Here's how:
- Go to the Gear icon and select Account and Settings.
- Select Advanced.
- Under Other preferences, turn off Warn if duplicate journal number is used.
- Select Save and Done.
Once done, please open the pay run and select Export to QuickBooks.
Let me know if you have any other questions and we're here to help you.