I know how to delete/cancel individual Highrise or Basecamp accounts, but I’m interested in deleting the global 37signals ID (the one used for the Launchpad) and so far I haven’t found a way to do it.
So, how can I completely delete a 37signals ID?
To my understanding, deleting a global 37Signals user ID requires a special Support request.
There are various ways to contact 37Signals Support ... assuming you're a Basecamp account owner, you can go here: https://help.37signals.com/bcx/tickets/new. Provide them the user's name and email; and let them know you'd like the user's global Launchpad ID to be deleted.
(Alternatively, you could effectively "disable" the user by simply removing them from all 37Signals accounts [Basecamp, Highrise, etc.]).