Status as a part-year resident typically applies to an individual who enters Canada for the first time as a resident, or who leaves Canada permanently. A U.S. resident who becomes a Canadian resident for tax purposes in any given year (because of factual considerations such as moving to a permanent residence in Canada), or a U.S. resident who is also a Canadian resident but decides to permanently leave Canada will likely be considered a part-time resident of Canada in both the year of entry and in the year of departure. Part-time residency status applies to individuals who have ties in Canada that have been severed mid-year.
In these situations, the ITA alters the “taxation year” of the individual to be the part of the year that the individual was in Canada prior to departure, or the part of the year that starts when the individual entered Canada and ends at the end of that calendar year. For the part-year
that the individual is a resident of Canada, he or she is subject to taxation on worldwide income. For the part-year that the individual is a non-resident of Canada, he or she is only subject to taxation on Canadian sourced income.