You can insert this formula in B2 with your first data cell in A2 and copy down
I use the data range A1:A24 in this example (A1 = the header)

=IF(COUNTIF($A$1:$A$24,A2)=1,"Unique",IF(COUNTIF($ A$1:$A$24,A2)=0,"Empty","Duplicate("& COUNTIF($A$1:A2,A2)&")"))


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Regards Ron de Bruin
http://www.rondebruin.nl/tips.htm


"lehigh46" wrote in message ...
Hi All,

Column A has hundreds of item numbers.
Most are NOT duplicated, but I could have as many as 10 to 15 item
numbers with duplications and each number could be duplicated 3 to 10
times or more.

Question:

I need a formula for column B which will return a unique number for
each set of duplicates.

I appriciate any help you can give me.