The T1 General Income Tax and Benefit Return is the tax return used by individuals to calculate their annual tax liability and get federal or provincial benefits such as the GST/HST Credit. It summarizes the taxpayer's income, deductions and tax payable as computed on supporting forms and schedules and calculates the taxpayer's refund or balance due. There are five parts to your T1 form including identification, total income, net income, taxable income and a refund or balance owing. Your T1 form and any balances owing for each year are due by April 30 of the following year or June 15 for self-employed individuals or common-law partners. If these deadlines fall on a Saturday, Sunday or public holiday, then they are extended to the next business day.