Yes, this can be done. Change the Allow field to "Custom" Enter the
following formula:

=AND(LEN(A1)=10,COUNTIF($A$1:$A$10,A1)=1)

HTH,
Elkar


"dandiehl" wrote:

I would like to perform two unique validation on the same cell. For
instance, I would like to ensure the cells A1:A10 only contain 10 digits
(phone number) and also that there are no duplicates in the range.

Can this be done?