Put this in the first row of an unused column and copy down as far as you
like...

=IF(A1="","",IF(ISNUMBER(--RIGHT(SUBSTITUTE(A1,"-","x"),7)),IF(ISNUMBER(--RIGHT(SUBSTITUTE(A1,"-","x"),8)),"No","Yes"),"No"))

Rick


"Omar" wrote in message
...
Dear Experts,
I have one column with 4424 rows represents customer's phone numbers
as follow.
971-4-5735403
How can I know if the last part (5735403) contains seven digits only?
Many thanks in advance
Omar