Can I subtract one list from a second list?

My client sent out a mailing of 9,000 names. Over time 2,000 of the 9,000 became customers and are in a current customer excel file. Is there any way to subtract the 2,000 current customers from the 9,000 original prospects to send out a new mailing of 7,000 names?

Did those 7000 souls ask to be kept informed of any exciting new offers?

Or are you really just aiding a mass email solicitation (Spam)?

You simply need to use a VLOOKUP against the data in the original list (remember names may not be unique so you may need to join a few fields together to be more certain).

If your names are in A1:A9000 on Sheet1 and your 2000 new customers on sheet2 in the same book, A1:A2000 then in B1 on the first sheet enter

=IF(ISNA(VLOOKUP(A1,Sheet2!$A$1:$A$2000,1,FALSE)),"","x")

This will put an x next to the names in the 9000 that have a match in the other list of 2000