Yes. You can add a trial balance to an existing workpaper, as long as it was created as an Annual Compliance workpaper.
Open the workpaper.
Select Trial Balance from the workpaper navigation.
At the top of the page, you'll see two options:
Update — manually upload a trial balance in CSV format.
Switch to Xero — appears if the entity is linked to a Xero file. Select this to pull the trial balance directly from Xero.
