Your UPC #s would have to be in ascending order for lookup to work. Instead
try using a MATCH function along with INDIRECT:

=INDIRECT("Sheet1!B" & MATCH(C20,Sheet1!A:A,0))

HTH,
Paul


--

"Heather C" <Heather wrote in message
...
I'm trying to match a UPC # to an Item number on an invoice. I put the
formula in and it bring up thewrong item number. I'm not quite sure how
to
fix this. The formula I'm using is
=IF (A200, LOOKUP(C20,Sheet1!A:A,Sheet1!B:B),"")

PLease HELP