Complex access level question
I am trying to setup a security site where users login with username/password.
I will be charging my client companies an annual membership fee, and then allow their employees to register using their email, password, and then a "company code".
I want to be able to control access by the company code, so that if a company doesn't renew, all of their employees lose access to the site, and are unable to register going forward.
Can security assist do this, or will it require extensive hand coding?