Try:

Data Validation==Custom==

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

Cells are formatted as number

HTH

"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?