This issue has been brought up on so many forums and threads, CRA should really have it written out somewhere so it is clear. and so many providers have had different experiences based on who they have talked to. Personally, no, I do not provide it and I put on my receipts that it will be provided directly to the CRA upon request. I do not provide it because I do not feel comfortable having my SIN "out there" any more than necessary. If I had a parent being audited I would tell them to have their auditor call me directly. I can then provide them with whatever I need. I also have my name address and phone # on my receipts.