Duplicate SSN During Open Enrollment

Just curious how other clients handle duplicate tax id errors during open enrollment?

Here is the scenario:

Employee is enrolling a beneficiary.  They get a duplicate SSN error when they enter in the SSN number of the beneficiary.  The beneficiary already exists as a Customer in the system.  When you update to the live table the record Search Type remains a "C".

How do others handle this scenario?  Have one record that is a search type "C", but now it is hard to report on all your dependent/beneficiaries or change the search type to Q?

Just curious what others would do.