help needed in conditional formatting

[karthik_kaliappan]

I have a data in sheet and in a column I have few event ID which are unique but there are chances that it may get duplicated as they are enetered manually, so is there a formula which I can use in conditional formatting so that the duplicates are highlighted

thanks,
karthik

 

[Jonmo1]

=Countif(A:A,A1)>1

 

[karthik_kaliappan]

thank you very much

 

[karthik_kaliappan]

thank you very much