How to prevent duplicate value

[MA96]

Dear All,

how to prevent duplicate value in VBA Excel ?

thanks

[georgiboy]

You can do this with 'Data Validation'

If your data is in column A then:

Select the whole of column A
Goto 'Data' in the ribbon
Select 'Data Validation'
Change the 'Allow' dropdown to 'Custom'
Enter formula: =COUNTIF(A:A,A1)=1
Click OK

Then try an enter a duplicate in column A