The only guarantees in life are death, and taxes! Everyone has to PAY income tax on their earnings, and your annual tax return is simply a recalculation of the amount of income & other taxes you owe, compared to the income tax you may have already paid (withheld on your paychecks). People who are self-employed, HST registered, OR earn a lot of income in cash Tips, may have an income tax balance due on some or all years calculated. You are legally required to file ALL tax returns for years when you owe more income tax.