=isnumber(match(a1,sheet2!a:a,0))

Will return TRUE if there's a match. False if there is no match.

Chatnoir11 wrote:

I have two worksheets with lists of customers. I'd like to lookup each
company on worksheet A and see if it is also on Worksheet B. If it is, then I
just want an "X" or a 1 or a simple response like that. I couldn't seem to
make a VLOOKUP work or MATCH. Should I create a column with "X" in it on
Worksheet B and have that column returned as the value on Worksheet A?

--

Dave Peterson