You don't have to declare non-residency to CRA if you never became a resident in the first place.
If you had spent time in Canada before, worked, filed taxes etc. and then move, you have to declare non-residency to CRA if you want to be able to stop filing. CRA may or may not accept your request depending on your ties to Canada.
If you just landed as a PR but you did not move to Canada, did not work in Canada and do not own assets in Canada, then you never became a resident for tax purposes and therefore do not have to file.
CRA says this: http://www.cra-arc.gc.ca/newcomers/#nwc
You become a resident of Canada for income tax purposes when you establish significant residential ties in Canada. You usually establish these ties on the date you arrive in Canada.
and it links to this: http://www.cra-arc.gc.ca/tx/nnrsdnts/cmmn/rsdncy-eng.html
Significant residential ties to Canada include:
* a home in Canada;
* a spouse or common-law partner in Canada; and
* dependants in Canada;
Secondary residential ties that may be relevant include:
* personal property in Canada, such as a car or furniture;
* social ties in Canada, such as memberships in Canadian recreational or religious organizations;
* economic ties in Canada, such as Canadian bank accounts or credit cards;
* a Canadian driver's licence;
* a Canadian passport; and
* health insurance with a Canadian province or territory.
So just having applied for a SIN card, a health card or a drivers license does not establish significant ties but buying or renting a home and/or leaving your spouse and/or children in Canada would.
