Creating a professional freelance invoice is vital to the success of your business. If you sent your client paper receipts and scribbled notes, they would not be as likely to pay you on time and would probably question the you run your business.
Invoice details: 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. It doesn't matter what kind of numbering system you use, just make sure it's in sequential order so you don't get confused.