Once you assign specific tax class to inventory item, tax rate of that class will be implemented on the inventory item. You can manage tax class settings from the settings of the repair desk.
1. Go to Inventory >> Manage Inventory >> Mobile, accessories & Parts
2. Open an item by clicking on its Item ID or by clicking on the Action button and selecting Edit.
3. Under the Prices tab, you can see options to select tax class and select its inclusiveness.
4. Select a Tax Class such as sales tax from the drop down menu. To add or change tax classes, go to Settings >> Tax.
5. Click on the Tax Inclusive option to assign tax to this inventory item.