Unique Values

Hi Christianna

Thank you for your question.

There are a couple of ways of doing this. The following method works if your unique values are in Column A

Highlight column A by clicking on letter A
From the Data menu choose Data Validation and select custom.

In the formula cell paste in the following formula

=COUNTIF($A:$A,A1)<2

This formula counts within column A for the value you enter. If it finds more than one the validation alert will appear. You might want to modify the warning text to explain to the user that values should be unique.

Be aware that the user could paste values into a cell in column A and no message will appear. The check only takes place when the user presses enter after keying into the cell.

I hope this helps - let us know how you get on.

Kind regards,
Andrew