(I posted this question in the Excel functions forum, but I'm not really sure that's the right place) I am an Excel novice, so I hope this is the right place for me. I have a list of about 50,000+ rows of names (that I can reduce to 20,000+ if I have to). The list has about 15 columns with various information - address, phone, county, license number, several dates, etc. I get this list sent to me once a month. What I need is to find just the new names on each new list. The license number is the only thing I have found that both stays the same and is unique to each person, so I can use that as a filter, but if I use an advanced filter/unique records only, I will get names from the old list that are not on the new list which I do not want. Is there some way I can do this without taking all day and making my eyes cross?

Laurie