Before creating a new SMU ID for a person, you MUST first do a thorough Search/Match. You can search on any combination of the available fields, but the least restrictive Search/Match which must be performed to be certain the person does not already exist in the system should consist of the following 3 fields:
NID (SSN) if available.
Last Name
First Name Initial.
See the 'Using Search/Match' documents for instructions on performing a Search/Match. Next Step