While this is helpful info, with a file of 23,000 names and addresses, there
were well over a thousand dups that showed up, some with 3 or more dups.
Since all of the duplicate data including the first occurence had a
"Duplicate" in the next column, I used autofilter to list all the dups, but
I still had to delete the actual dups manually. Also, in excel 2000 the
method mentioned at cpearson to add "duplicate" to an adjacent column so you
could autofilter the results caused my computer to repeatedly crash until i
did smaller sections of data at a time.

What i would like to know is : how do you leave the first occurence of the
data, and mark only the dups (trips etc). The suggestions in this forum mark
all occurences of the duplicate data. I would like the first occurence of the
same address to be a 0 and each succeeding occurence to be a 1 or greater so
that i can autofilter and then delete everything over 0, not have to delete
the rows out myself.

" wrote:

See;

http://www.cpearson.com/excel/duplicat.htm