User account deletion on free plan

Is it possible to delete previously invited users on the free plan?
I currently have "4 total users", but cannot add a 5th without upgrading, which is strange.

I should simplify the first question to this: Is it possible to delete users on the free plan ?

We can archive users for you.

Thanks. If I move to the Plus plan, is it possible to delete users directly or necessary to request to archive a user ?

At the moment, you cannot remove users. If you would like me to archive them, let us know.

Ok thanks for the info.