How to recover my MS office license key

You access the MS Account associated with that original Office install to de-activate the original install then install on the new https://office.com/myaccount (You need to uninstall the pre-installed O365 Family Trial first)

If it was not associated with an MS Account, you would need original install media and the Key that was in your paperwork

Hi HARI P! I am Shakiru, an independent advisor and a user like you, and I am glad to be helping you out today. Please note that once you have associated your Microsoft Office pack with your Microsoft account, then your Microsoft account login credentials (email and Password) become your Office license key that will be used for activation after installing it on a new laptop. Please let me know how it goes and if you need any other assistance and I will be more than happy to help further. Thank you Best Regards, Shakiru

Hello

Do you know what version of Mac OS is on the older Mac? It's important to know because during the Office 2016 time frame Mac OS went from supporting 32-bit software and then requiring 64-bit software. Office 2016 started off as 32-bit but ended as 64-bit, so the update version is critical.

If your old mac has been upgraded to 64-bit only Mac OS and it has the 64-bit version of Office 2016, then you can use Apple Migration Assistant to bring your applications forward and your license should travel with the migration.

On the other hand, if your old Mac has 32-bit Mac OS and and Office, then you won't be able to use Migration Assistant to bring everything forward. You won't be able to install or run Office 2016 without the product key.

Given the age of Office 2016 and the number of improvements made to Microsoft Office, I suggest getting a subscription for Office 365. If you prefer to have a permanent license, get the subscription month-to-month and wait for Office 2024 to come out later this year. That will provide you with the longest license coverage as Mac OS gets upgraded over time.