If you are doing any type of business you will need an invoice, which looks good, as this simple sheet of paper will represent your company. Also it’s a way to receive payment from your clients, where you can clearly state payment terms.
This is common invoice template which is easily editable in excel.
This file works both on windows and mac.
In this excel worksheet you will find few spreadsheets with different kind of templates. I am using these simple templates for my business, as it only takes like one minute to write full invoice.
Also I always save this file as new one, firstly I enter business name or last name of person which bought something from me and the date when the deal occurred. This helps me to find invoices at the later time when I need them.