Clients with different attributes that are not all the same.

I have been given the project of building a master client database. I work in a financial environment where we client/product/account information. For some types of client they have specific information related just to them, unique identifier, name, but they differ in the other information that relates to them. For example, Client A may have a 4 character unique identifer with no product information, Client B may have a 9 digit unique identifier with the possibilty of product information based upon a platform. Finally Client C has a 4 character unique identifier with production information. The product information is based upon a System/Prin/Agent (4 digits each) Each client represents a different platform, of which a client can be on multiple platforms.

What would be the best method for this situation? One dimension table could have lots of null values for all of this information. The clients do have some attributes in common such as name, address, phone, etc. They just have different ways of identifying themselves. Should I split the clients out into their own client table with a common key to a main client table. Dimension with a snowflake?