You'll want to establish a formal salary sacrifice arrangement first, before any work is performed, to successfully set up a pre-tax salary for a car or motor vehicle in QuickBooks. This allows the employee to direct a portion of their pre-tax salary toward a motor vehicle and its running costs.
Once finalised, please ensure you've already created custom salary sacrifice deduction categories so you can manually map them to the Salary sacrifice (Other employee benefits) classification.
You can follow the steps below:
Open All apps, click Payroll, and choose Employees.
Access Payroll Settings.
Locate Deduction Categories under Pay Run Settings.
Select the newly created car deduction and update its Classification.