How to allow unique values in three columns

[lamp123]

I want to create a validation which will allow unique row of first name, last name and email. When I enter a new row, it should not allow if the same values already exist in previous rows.

First Name Last Name Email
John Doe [email protected]
Scott Doe [email protected] - should be allowed
John Doe [email protected] - should not be allowed
Robin Scott [email protected] - should be allowed.


How do I achieve this. Thank you.

[BenMiller]

With your data in columns A:C, assuming no header row, select starting from A2 and down until the bottom of where you want to validate in column C and enter this formula for the validation: =NOT(AND(COUNTIF($A$1:$A1,$A2)>0,COUNTIF($B$1:$B1,$B2)>0,COUNTIF($C$1:$C1,$C2)>0))

[lamp123]

Thank you. Appreciate quick reply.

[BenMiller]

No problem Glad I could help ... Appreciate the feedback!