Microsoft Office 2019 Professional Plus Bind Key. This unique product key is used to activate Microsoft Office 2019 Professional Plus, which includes a suite of applications such as Word, Excel, PowerPoint, Outlook, and more. This version is designed for professional use, providing advanced features and tools that enhance productivity and collaboration in business environments. To ensure proper functionality and access to updates, it is essential to enter the activation key during the installation process. It binds to your existing email.