How to Add a new expense category

The Expense Category feature allows you to create a new expense category and include details such as the tax code, general ledger mapping code, tax rate and external ID. 

Go to Payroll setting > Expense category. 

Click on Add

Next in the add expense category menu enter the name of expense category, Tax code and tax rate. However, tax code can be left empty as it is manually entered in the odoo.