If you are a business owner or accountant, you may need to know how to add billable expenses to an invoice in QuickBooks Desktop in order to accurately track and manage your finances. This is especially important if you are dealing with clients who need to be billed for expenses related to their projects. Knowing how to add billable expenses to an invoice in QuickBooks Desktop can help you ensure that you are accurately tracking and billing for all of your expenses, and that your clients are being billed correctly.