Assuming List 1 of 80 in Col A of Sheet1 and List 2 in Col A of Sheet2...
Enter this in B1 of Sheet2
=IF(ISNA(VLOOKUP(A1,Sheet1!A:A,1,FALSE)),"Not in List 1","Present in List 1")
and copy down till end of your data

In B1 of Sheet1 you can have
=IF(ISNA(VLOOKUP(A1,Sheet2!A:A,1,FALSE)),"Not in List 2","Present in List 2")

for the reverse

"CapFSU" wrote:

have a sheet w/ list of 80 different 6 digit codes. have a second sheet w/
over 13,000 8 digit codes. Trying to figure out how to lookup in the second
list to see if any of the 13,000 first 6 digits of the 8 digit code match any
of the list of 80. Any ideas?