BTW for all you idiot landlords. I mean fuck, the government does everything it can to make you the tenant's bitch, one would figure you should know better if you are going to be in that business. But continue to pretend that you actually own your units.
http://www.priv.gc.ca/faqs/index_e.asp#q012
You are not required to provide your SIN number to any other private-sector organization or person such as a landlord. There is no law preventing private-sector organizations from asking for the SIN for other purposes, such as identification,
but they do need to make people aware that collection of a SIN is optional and not a condition of service.
Our Office recommends that no private-sector organization request the SIN from a customer, and that no customer give the SIN to a private-sector organization, unless the organization is required by law to request it.
and
http://www.priv.gc.ca/cf-dc/ser/2006/s19_060203_e.asp
Commissioner's Findings
Settled case summary #19
SIN not required when signing apartment lease
Complaint
A student complained that he was unable to rent an apartment without providing his SIN to the property management firm.
Outcome
The property manager told us that his firm required the SINs of potential renters in order to verify identities, conduct credit checks, and, if necessary, contact collection agencies.
However, the federal government, in an effort to prevent the SIN from becoming a universal identifier, issued a policy limiting the collection and use of the SIN to specific acts, regulations and programs. While there is no legislation that prevents organizations from asking for the SIN for other purposes,
such as identification, organizations that are subject to the Personal information Protection and Electronic Documents Actmust clearly indicate to the customer that provision of the SIN for identification purposes is optional and not a condition of service.
The manager therefore revised the lease agreement so that a driver’s licence is the only piece of identification required. He no longer requests SINs from potential lessees.
Upon learning of the changes the property management firm instituted as a result of his complaint, the student and the Office considered the matter to be settled.
and
http://www.ohrc.on.ca/en/learning/can-i-ask/sin
A Social Insurance Number (S.I.N.) isn't needed for renting property. The information on a S.I.N. could be used to discriminate.