Preventing Duplicate Entries within a column

[Bruce]

Is there an easy way to prevent creating duplicate
entries within a given column in Excel?
Alternately....is there a way to automatcially highlight
a cell / row when a duplicate entry is created within a
given column?

 

[Guest]

If they are typed in yes it is easy

http://www.cpearson.com/excel/NoDupEntry.htm


or to tag them

http://www.cpearson.com/excel/duplicat.htm


Regards,

Peo Sjoblom

 

[Jim May]

Assuming your entry-range begins in A3 and downward to A100
Select Cell A4, then at the menu, select Data, Validation, Allow: Custom
In the formula Box enter:
=IF(COUNTIF($A$3:$A4,$A4)>1,FALSE,TRUE)
then OK (out).
While A4 is Blank or empty, Copy it and paste from A5:A100.
Done.
HTH

 

[Rob van Gelder]

To highlight duplicates:
Select column A
From Format menu | Conditional Formatting
Formula Is: =COUNTIF($A:$A, $A1)>1
Then format as Bold, or Red or whatever.