Quote Originally Posted by NBVC View Post
Perhaps your version of Excel requires argument separators to be semi colons instead of commas. Try:

=COUNT(1/FREQUENCY(IF($B$2:$B$25=E2;IF($A$2:$A$25<>"";MATCH($A$2:$A$25;$A$2:$A$25;0)));ROW($A$2:$A$25)-ROW($A$2)+1))
confirmed with CTRL+SHIFT+ENTER
Worked like a charm!!!

Turns out I needed to use commas instead of semi-colons...not sure why that is. Thanks so much for your help!!