While the obligation to file a tax return recurs annually, that return form is never exactly the same from year to year. Tax brackets and allowable deduction and credit amounts change each year and, more significantly, new deductions are provided for and new credits allowed or eliminated.
Each year, the Canada Revenue Agency (CRA) publishes a statistical summary of the tax filing patterns of Canadians during the previous filing season.
Income tax is a big-ticket item for most retired Canadians. Especially for those who are happily free of the requirement to make mortgage payments, the annual tax bill may be the single biggest annual expenditure they are required to make.