That way, you can match the correct version using your list later once you obtain the last five characters of the current product key on the PC. Your only option is to keep track of your device installs and the corresponding Office versions. The bottom line is there is no way to obtain the full Product Key using commands or third-party software unless you use Office 2010 or earlier. The image below applies to Microsoft Office 2013 and newer, even though they are pushing their 365 subscriptions. Unfortunately, Microsoft made changes beginning with Office 2013, where only the last five digits of the product key get stored on your PC. Each one has specific methods for installation and reinstallation, as well as how the product key gets stored and used. There are four types of Microsoft Office software: Retail, Subscription, Volume, and OEM. It’s difficult to find, so you might be panicking trying to remember the lost activation code.
If it's hard to read the product key on your packaging, use this guide to help you tell the numbers and letters apart:
If you lose your Product Key and have a valid proof of purchase, contact Microsoft support for help.
Keep the packaging, or write the number down and keep it in a safe place.