The Employee ID is a unique identifier for anyone who has been paid in the Data Processing system regardless if they are paid as an Employee or as a Service Provider or Honorarium Recipient. The Employee ID is now required in all requests for people who you have paid in the past as there is no longer a field for SIN or Date of Birth for security reasons.
The decision to remove SIN and Date of Birth as an identifier for individuals who have been paid in the past was implemented by ICT Security and the university's Security Officer. However, SIN and Date of Birth is still a requirement by CRA for anyone who has not yet been paid. For your information, the data in these fields is removed once the request has been resolved.