Excel - Count unique values on multiple criteria

Question

My head is just sort of spinning on this and the solution examples. Can someone please provided a solution for this specific issue? Once I see it for what I need then it click

Answer 1

This is essentially the same method as the response from Scott Craner but incorporates dynamic column length.

=SUMPRODUCT(((D$2:INDEX(D:D, MATCH(1E+99, C:C))=H2)*(E$2:INDEX(E:E, MATCH(1E+99, C:C))=I2))/
            (COUNTIFS(C$2:INDEX(C:C, MATCH(1E+99, C:C)), C$2:INDEX(C:C, MATCH(1E+99, C:C)),
                      D$2:INDEX(D:D, MATCH(1E+99, C:C)), H2, E$2:INDEX(E:E, MATCH(1E+99, C:C)), I2)+
            (D$2:INDEX(D:D, MATCH(1E+99, C:C))<>H2)+(E$2:INDEX(E:E, MATCH(1E+99, C:C))<>I2)))

This formula's dynamic column length does depend on the accounts being true numbers.