Hi,

I am looking to count the unique amount of customers who are listed in column C based on the criteria that they purchased the product on the 1/08/2014 and that the product came from Department 3. The output I am looking for in this example would be 3. I can do it for this example but when I have 300 different customers it starts getting tricky and I'm a bit stumped on how to incorporate an array formula into a countifs() function or whether there is an alternative.

Date Department Customer
1/08/2014 3 A
1/08/2014 3 B
1/08/2014 2 C
1/08/2014 3 D
4/08/2014 3 A
5/08/2014 2 A
5/08/2014 3 D

Cheers