Master Client

SUGGESTED

I have never set up any of our clients as Master Clients before.  Our clients are simply set up with references.  Once a client is set up, can it be switched and set up as a Master client or does it need to be set up as a Master client from the beginning?  I thought it needed to be set up from the beginning because that way every sub-matter would have it's own A/R.  As we have it set right now the client has one A/R.  Also, it seems that having some clients as Master client with sub-matters and others set up with references will affect the reports as well.  Is this correct?