If you're unable to find your product key or if it's not working, consider the following alternatives:
Users with MSDN or specialized Microsoft developer accounts may have access to Mondo keys for testing purposes.
Because of its unique origins, here are some intriguing details about its licensing and behavior:
Mondo was never intended for general public distribution or long-term personal use. Why is My Office Showing as "Mondo 2016"?
Most Mondo licenses are strictly for development and testing , not commercial or personal daily use.
Here are some common issues that you may encounter with product keys:
If you purchased a legitimate copy of Office 2016, the key is tied to your Microsoft account rather than the "Mondo" tag.