Internet access is required to install and activate the latest versions of Office suites and all Microsoft 365 subscription plans. Internet access is also required to access documents stored on OneDrive, unless the OneDrive desktop application is installed. A regular Internet connection is required to keep the Office version up to date and to take advantage of automatic updates. If you do not connect to the Internet at least every 39 days, the applications will go into reduced functionality mode (meaning that you will be able to view and print your documents, but you will not be able to edit them or create new ones). To reactivate Office applications, you need to reconnect to the Internet.
You do not need to connect to the Internet to use Office applications (such as Word, Excel and PowerPoint), as the applications are installed on your computer.