Eduardo, than you for your quick reply. I would have responded sooner I have
been having a hard time trying to make your solution work, and was
unsuccessful -all, came back "#N/A". I must be doing something wrong. Could
you please elaborate, I am not an Excel power user.

Thanks.

"Eduardo" wrote:

Hi,
if you apply a vlookup then everything that shows as #N/A means that are
missing from the other list

Let' say your File A is in sheet1 and File B in sheet2 starting in cell A2,
in B2 sheet1 enter

=VLOOKUP(A2,Sheet2!A1:A25000,1,FALSE)



"Jerry" wrote:

I have two different files, both use the same unique identifiers. How can I
ascertain which records are missing from the smaller file.

For example:

File A, has 28,225 different records.
File B, has 14,205 different records.

Which records from File A, are missing from File B?

Thank you, Jerry