Along with the payment terms, you can specify whether you charge a late fee for invoices paid past their due dates. Some freelancers like this option, to enforce getting paid on time. You may also want to include your tax ID number in this area for tax purposes.
You can attach files—such as a detailed time report, design drafts, or additional project information—to an invoice before sending it to your client. You can also attach an Expense Report, which will contain receipt images entered with your expenses.