SaaS User & Client User DB Structure


I’m sure this has been asked several times, and I have done a search of which I’m struggling to find the best solution.

If I create a SaaS application where my customers, who can login, will have their own customers that can also login, what is the best way to structure the database?

The primary User data type is the only one you can use for logins if I’m not mistaken?

So this would need to be use in same way to store both my customers logins and my customers customers logins.

What’s the best way to differentiate the two?

I though of having separate data types for each type of user to store the relevant fields for that type of user.

Then in the primary user data type a field called ‘User Type’ which by default would be ‘Client’ for my customers, customers. So when their customers sign up the user type is client. If my customer signs up they create an account and the user type is changed to ‘Customer’. Then certain things are visible/hidden depending on user type, or is this a terrible way of doing it?

Many thanks,