How to Install, add Key and activate Office 2021 completely offline

Question

We have a completely airgapped set of laptops. We have purchased multiple copies of Office 2021 Home&Business. They were purchased directly from the Microsoft store. The ISO is the "offline" download.

Once installed, all office apps are there and have a 5 day ticking clock. However, the screen for telephone activation doesn't seem to exist. We are unable to bring it up. Additionally we just get an error message after the key is entered. We have tired using the CMD commands listed below to avail.

cscript.exe "%ProgramFiles%\Microsoft Office\Office16\ospp.vbs" We tried every argument, none worked. When using dstatus it shows "Office 2021 Home and Business (grace).

Please help! We spent thousands on these licenses after being told that we could activate them offline. We can't even bring up the telephone #. Just a generic "unable to activate online""

We do not have a KMS and there is absolutely zero chance of connecting any of the workstations to any network, let alone the internet.

Answer 1

I have the same case. We have an offline network and have to have a solution for it to active the office on these machines. These PCs never contact the Internet because of an internal Policy. I know on at least Office 2019 it was possible to activate via phone. @Microsoft please come up with a solution. We have a O365 subscription for each user but we can't use it on Lab PCs which are always offline.