Forcing patrons to input 7 or 10 digit phone numbers

Former Member
Former Member $organization

Our Marketing group is considering an outbound sales campaign, and during their research they noticed many patrons inputted incorrectly formatted phone numbers when creating an online account. 
Some phone numbers have fewer than 7 digits; some have more than 10. 

I know there are problems with forcing phone numbers to fixed lengths, but still wondering:  Has anyone implemented this in their system?


Many Thanks
Wendell Baskin
Bass Hall - Fort Worth