The Canadian Revenue Agency (CRA) makes a distinction between a Grant PDF and an External PDF. Because Grant PDFs are viewed as employees, they are eligible for certain benefits. External PDFs, however, are viewed as trainees and are not eligible for benefits. According to Policy R50.03:

• “Employment benefits are available only to Grant PDFs; required and optional benefits are described under "Procedures for a Research Grant Appointment," a supplement to SFU Policy R50.02. As noted in that Policy, hours of work, vacation, maternity and parental leave, and termination of employment for Grant PDFs are governed by the Employment Standards Act of B.C. Deductions from the PDF’s salary are made for the employee's contribution to the Employment Insurance program, Income Tax and Canada Pension Plan. A clear description of the specific benefits offered to the Grant PDF should be in the Appointment Letter.
• External PDFs are not eligible to receive employment benefits from SFU. They are required to make private arrangements for medical insurance coverage. No deductions are made from their stipends for Income Tax. PDFs should be aware that tax may be payable when a tax return is filed. These facts should be made clear in the Invitation Letter.”   (SFU Postdoctoral Fellows Policy, R50.03)

To summarize, a Grant PDF is treated as an employee, and therefore, their employment is governed by the Employment Standards Act of B.C. An External PDF, however, is treated quite differently. An external PDF is not eligible for Employment Insurance (EI) or Canadian Pension Plan (CPP), and the payroll office needs to be alerted to this at the point of set up. The Letters of Appointment/Invitation are vital as these letters explicitly state the type of PDF and what benefits they are eligible for.