Hi jason, The problem was in the formula
try =COUNTIF('SHEET1'!A1:!A2500,A1)
"Jason K" wrote:

I am trying to see if a policy number (ex. ml001122) appears on a sheet. I
have a list of about 300, and want to know if they appear on another sheet
and how many times they appear. I have tried using the formula
=COUNTIF('SHEET1'!A1:'SHEET1'!A2500,A1) but it keeps coming back as 0. The
first sheet has more than two thousand rows, and on the second sheet I have
about 300 policy numbers to check. I need to see if those numbers are on the
first sheet.

Thanks for any help