OOEM Product Key is a unique character alphanumeric code used to redeem and activate your Office product. Buy OEM Microsoft Office Standard 2019 user Standrd install the Office apps on up to 5 phones and 5 tablets 2. Mobile versions of Office applications Clickable Miccrosoft in header Buy OEM Microsoft Office Standard 2019 expand 1 table rows below. The applications are not automatically updated; to get the latest version, you must purchase Office again when the new version becomes available. How do I obtain a backup copy of my Office product? Office is a one-time purchase that comes with classic apps like Word, Excel, and PowerPoint for PC or Mac, and does not include any of the services that come with a Microsoft subscription. Windows Office Surface. Set up mobile devices. A one-time purchase installed on 1 PC or Mac for use at home or work. Support and resources. The copy of Office on the device you deactivated will revert to read-only mode, which means documents can be viewed but not edited.