Generally, your contact info should be on the opposite side of the recipient's info. So if your business name and logo are on the right side of the invoice at the top, the client's name and info should be below this on the left side.
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. Take the stress out of getting paid by using a free template or an invoicing system to track your work and start getting paid on time.