Across from where you put the recipient's name and contact info, include the details of your invoice. This placement makes it easy to keep track of vital information — for both you and the recipient. You'll want to include: Invoice Number, Date prepared, Payment due date.
Below the total you can include any additional information, such as a thank you or a reminder. - When you work out the contract with each client (and yes, you should have a contract in place!), you'll list out the terms of how often you plan to invoice and when you should be paid. For instance, you can agree to bill on the first of each month, or biweekly so you get paid every other Friday.