I received a question from one of my friends last week and thought of sharing my response here. He has worked in two provinces during the year and wanted to know which tax package he should use.
In general you determine the tax package of the province or territory you lived on Dec 31st of the year. But if you had residential ties in more than one province or territory on December 31st, you should use the province or territory where you had most important residential ties.
Residential ties include where your home (owned or rented) and personal property are and where your spouse or common-law partner or dependants reside. Other ties that may be relevant including social ties, driver's license, bank accounts or credit cards, and provincial or territorial hospitalization insurance.
Here are some other exceptions.
§ If you are filing a return for a person who died in during the year, use the package for the province or territory where that person resided at the time of death
§ If you emigrated from Canada during the year, use the package for the province or territory in which you resided on the date you left.
§ If you lived outside Canada on December 31, but maintained significant residential ties with Canada, you may be considered a factual resident of Canada. Use the package for the province or territory where you kept your residential ties.