user registration without email invite

It's that I don't want to send an invite. The system is not working. There have been many problems with QB's email system of the last week and many notifications, reminders and subscriptions have been going out. Most recently two invites never made it to the recipients. I need to be able to have these new users access the system. This is critical to our operations. Therefore I am looking for a workaround to the standard email invite method of getting a user registered.