Try using 111-11-1111. That works on an app that we use that requires SS # for children being added as dependents.It means its worthless then. I'd say unless its the spouse sitting there you can rarely get the ss # . It means you'll have to call the client back at a later date to get it. Chances are they'll forget or won't answer the phone. Gives them time to back out. What about the paper app? Need ss #?