Third-party seller: You bought Office from a third-party and you're having problems with the product key. Some organizations have different methods to install Office on multiple devices. Volume license versions: If you work in an organization that manages your installations, you might need to talk to your IT department.
Microsoft HUP: If you bought Office for personal use through your company, see Install Office through HUP. Note: The steps to install the 2019, 2016, or 2013 versions of Office Professional Plus, Office Standard, or a stand-alone app such as Word or Project might be different if you got Office through one of the following: