Suppose you have the data in Col A starting from row 1 ...In B1 enter this
formula and copy that down. Once done copy paste special values to the same
column...

=A1 & "_" & COUNTIF(INDIRECT("A1:A" & ROW()),A1)

If this post helps click Yes
---------------
Jacob Skaria


"Vilish" wrote:

15604
15604
15604
15604
15604
16484
16484
16484
16484
16484
16484
19606
19606
19606
19606
19606
23064
23064
23064
23064
23064
23064
23734
23734
23734
23734
23734
23734
23734
I have got this data set and i wanted to give unique number for
ie.15604_1,15604_2 so on ... Can anyone please help me. Vilish