You can download invoice templates in other formats from here. Professional format with all essential invoice elementsįor more information on which fields are required for an invoice, check out our how to write an invoice guide.Completely free, blank invoice template ready to send to clients.This printable invoice works perfectly for standard 8.5″ x 11″ printer paper. Then you’re ready to email or print and mail the invoice. Simply download the file and fill out the customizable fields. This free blank invoice template is a simple and easy way to send a professional-looking invoice to clients.