An invoice is a document issued by a seller to a buyer for products sold or services rendered indicating the products or services, the agreed prices and other necessary info related to the transaction. There are softwares you can use to create invoices. There are also invoice templates you can download and edit with Microsoft office program.
You can find yourself in situations when you might not have access to a PC or the invoice templates you downloaded are not compatible with the version of Microsoft office installed on your PC. In such cases, if you have access to the internet, you can create professional invoices online with free templates at office.live.com. All you just need is an active free outlook account.
To get started, log on to office.live.com
Click on the "Excel Online" tab, then click on "Browse Templates"
Under the categories, click on "Invoices". You will see the available free invoice samples you can edit.
Click on the one you like, then on the new page that opens, click on "Open in Excel Online".
You can then customize it the way you want. As you are working on it, the changes save automatically and sync across all your devices where you might have installed the Microsoft Onedrive app.
Once you are through, you can click on "File" > "Save As..." > "Download a Copy" to save a copy to your computer after which you can send it as an email attachment to the recipient.
You can always access the invoice online at office.live.com and also via the Onedrive app installed on your PC and mobile devices.
I hope this helps.