可以使用多种方法来处理/实现它.让我分享一种方式:
您设计的数据库可以跟踪与公司绑定的userId的数量.

There can be various ways to handle/implement it. Let me share one of the ways:
Your database designed such that number of userId''s tied to a company can be tracked.

MstClients
ClientID ClientName AccessLimit

TrnClients
ID ClientID UserName

现在，这两个表始终可以跟踪每个客户端允许的用户名数量.

此外，您需要实现一次登录的逻辑，以避免多次使用同一登录名(如果您愿意！)

试试吧！

Now, these two tables at all time can track number of usernames allowed per client.

Additionally, you need to implement logic of having a single sign-on to avoid multiple use of the same login (if you want to!)

Try!