QuickBooks Online sync error: QuickBooks Online Business Validation Error: An account you chose for a billable expense doesn't have an income account associated with it.

Why the sync error occurs

In QuickBooks Online, when you turn on the setting for "Track Expenses and items by customer" and select to "Make expenses and items billable", you'll have a section to choose one of two options for the billable expense income account. You can choose to track in a single account or in multiple accounts.

The error occurs if you've chosen the second option for multiple accounts and it wasn't set up properly.

How to fix the sync error

In QuickBooks Online, to complete the setup properly for tracking in multiple accounts, all expense accounts used for billable expenses need to be edited. In the In multiple accounts sections, select Use for billable expenses and assign an income account. If this step isn't completed, this error will occur when marking an expense transaction billable.

To view and update what option you have selected, in QuickBooks Online:

1. Select the gear icon and select Company Settings
2. On the menu to the left, select Expenses
3. Select the Bills and expenses section
4. View your selection under Track billable expenses and items as income
5. Make any necessary changes

If continuing with tracking in multiple accounts, assign the desired billable expense account(s) to an income account to clear the error. The following must be completed by a QuickBooks Online Primary Administrator. Other users in the company file won't see Step 3:

1. Select the gear icon
2. Choose Chart of Accounts
3. Select once to highlight the desired expense account
4. Select Edit
5. On the Account screen, select Use for billable expenses and select an Income Account from the dropdown menu
6. Select Save