If you have your account numbers in Col A then enter this in B1 and copy down
=IF(COUNTIF($A$1:A1,A1)1,"Duplicate",A1)
Filter on Duplicate and delete those rows..


"April_2004" wrote:

I have a huge table with account numbers and I need to find out all the ones
that are repeated in one column so that I can delete them and just keep one
value (one Row)..

Does anybody know how to do this with VLOokup or some other function?

Thank you