Microsoft has made three new Office 365 plans aimed at small and mid-size business generally available as of October 2.

Microsoft announced back in July that it would make the new plans -- Office 365 Business, Office 365 Business Essentials and Office 365 Business Premium -- available for purchase starting October 1.

Office 365 Business Essentials , which includes email and calendaring (Exchange Online); online meetings, instant messaging and video conferencing (Lync Online); team sites (SharePoint Online); 1 TB of free OneDrive for Business cloud storage, and Yammer enterprise social-networking support. It doesn't include any downloadable Office apps. It will cost $5 per user per month, or $60 per year .

, which includes email and calendaring (Exchange Online); online meetings, instant messaging and video conferencing (Lync Online); team sites (SharePoint Online); 1 TB of free OneDrive for Business cloud storage, and Yammer enterprise social-networking support. It doesn't include any downloadable Office apps. It will cost . Office 365 Business , which includes the full set of locally installable Office applications (Outlook, Word, Excel, PowerPoint, OneNote and Publisher) for up to 5 PCs and/or Macs per user; and 1 TB of free OneDrive for Business cloud storage. It doesn't include Exchange, Lync or SharePoint online. It's just the software (and storage) sold as a subscription. It will cost $8.25 per user per month, or $99 per year .

, which includes the full set of locally installable Office applications (Outlook, Word, Excel, PowerPoint, OneNote and Publisher) for up to 5 PCs and/or Macs per user; and 1 TB of free OneDrive for Business cloud storage. It doesn't include Exchange, Lync or SharePoint online. It's just the software (and storage) sold as a subscription. It will cost . Office 365 Business Premium, which includes the full set of locally installable Office applications for up to 5 PCs and/or Macs per user; Exchange Online; Lync Online; SharePoint Online; Yammer enterprise social-networking; and 1 TB of free OneDrive for Business cloud storage. It will cost $12.50 per user per month, or $150 per year.

Brand-new Office 365 customers can buy these plans now. For existing Office 365 SMB customers, Micorsoft is planning to move users during the next year (or so) from the current Office 365 plans for SMBs -- Small Business, Small Business Premium and Midsize Business, which cost $5, $12.50 and $15 per user per month, respectively.

Microsoft's simplified guidance for those existing users wondering when and how they'll be transitioned to the new plans:

"If your business is currently on one of the previous SMB plans (Small Business, Small Business Premium or Midsize Business), you should visit your Message Center in the Office 365 admin center for more details on how the new plans impact you, or talk to your Office 365 provider. The current Office 365 Enterprise plans remain the same."