How to Create an Expense Category Open the Expense module and go to Categories, or expand Other Options while creating an expense and choose Add New Category. Enter a clear category name. Save the category. Useful categories include Salary, Rent, Utilities, Advertising, Insurance, Office Supplies, Repairs and Maintenance, Bank Fees, and Professional Services. Avoid creating several names for the same purpose, such as “Electric,” “Electricity,” and “Power Bill.” Consistent categories produce cleaner reports.