Office 365 Enterprise E1 works best with the new Office, Office 2013, and Office 2011 for Mac. Previous versions of Office, such as Office 2010 and Office 2007, may work with Office 365 with reduced functionality. You do not need a desktop version of Office to use Enterprise E1. However, you will receive a much richer experience and be able to work offline if you do connect a desktop version of Office to the Office 365 services.

You can pay with all major credit cards, and your subscription amount will appear on your credit card statement. You also have the option to receive an invoice and, depending on your choice of services, you will be billed monthly or annually. You receive an email message when your invoice is ready to be viewed and, if a purchase order (PO) number is entered when you buy your subscription, that number is included in your invoice.

Annual commitment payment is available for Office 365 Enterprise plans. With annual commitment, you sign up for a one-year subscription, but you can choose to pay month to month or pay for the entire year at the time you sign up.

Yes, discounts are available for Office 365 enterprise agreement customers (typically 250+ licenses) who want to purchase through volume licensing. A Microsoft expert can help you explore the purchasing options for large enterprises and help you determine which is best for you. Learn more about volume licensing. Find a Microsoft expert.