Using product keys with Office - Microsoft Support
Instead, for Microsoft 365, Office 2021, Office 2019 and Office 2016, you can view the Microsoft account that Office belongs to. This account takes the place of your product key and can be used to reinstall Office from the Microsoft account, Services & subscriptions page and to activate Office.
Applies To:
Excel for Microsoft 365, Word for Microsoft 365, Outlook for Microsoft 365, PowerPoint for Microsoft 365, Access for Microsoft 365, OneNote for Microsoft 365, Publisher for Microsoft 365, Visio Plan 2, Excel 2021, Word 2021, Outlook 2021, PowerPoint 2021, Access 2021, Project Standard 2021, Publisher 2021, Visio Professional 2021, Visio Standard 2021, Office 2021, OneNote 2021, Excel 2019, Word 2019, Outlook 2019, PowerPoint 2019, Access 2019, Project Standard 2019, Publisher 2019, Visio Professional 2019, Visio Standard 2019, Office 2019, Excel 2016, Word 2016, Outlook 2016, PowerPoint 2016, OneNote 2016, Project Professional 2016, Project Standard 2016, Publisher 2016, Visio Professional 2016, Microsoft 365 for home, InfoPath 2013