How to find duplicate records in Datalist

**TST** · 05-30-2008, 12:27 PM

Hi Everyone

I'm new to this forum but it looks great and SO informative. I joined to find an answer but am struggling, so here's my question if anyone can help please? I'm using Excel 2003.

I have a list of say 10,000 records - I'm happy with sorting, filters, subtotals etc. What I need is to find out if I have any duplicate records in my list.
Say Column A contains a National Security Number and everything on that row relates uniquely to that person. How can I find out if that same person has been entered elsewhere in the list? In other words, how can I find if the same N.I. number has been repeated?

Many thanks in anticipation

Diane

**NBVC** · 05-30-2008, 12:41 PM

Try something like this:

=Countif(A:A,A1)>1

copied down.. where you names are in column A starting at A1.

This will return TRUE if the name in that row appears more than once in your list.