A social insurance number (SIN) is a 9-digit identification number necessary for individuals to work in Canada and to have access to government programs and benefits. It ensures the accurate and efficient processing of applications by government financial aid agencies. 

At York University, a student's SIN is required for multiple distinct purposes: 

• Processing of Ontario Student Assistance Program (OSAP) applications and the distribution of OSAP funding. All communication and data sharing between York and the National Student Loans Service Centre (NSLSC) requires the SIN as the main identifier of the student. 

• Preparation of income tax documents that York is required to provide to all students who have been awarded a scholarship, bursary or other monetary prize. The SIN is also required for the T2202 Tuition Enrolment Certificate. 

• Documentation related to the employment relationship when students are hired by York for employment funded through the Work/Study Program. A SIN is required for employment and income reporting.