Corporate tax deadlines in Canada: T2, CO-17, AT1 and information returns

A corporation files its T2 Corporation Income Tax Return within six months of the end of each tax year, even when it owes no tax.

• If the tax year ends on the last day of a month, the T2 is due by the last day of the sixth month after it. A December 31 year end is due June 30.
• If the tax year ends on any other day, it is due by the same day of the sixth month after it. A year ending March 15 is due September 15.
• When the due date falls on a Saturday, Sunday or public holiday the CRA recognizes, a return received or postmarked by the next business day is on time.

Source: CRA, When to file your corporation income tax return.

The filing deadline is not the payment deadline. The balance of tax is due two or three months after the end of the tax year: three months for certain Canadian-controlled private corporations that claim the small business deduction, two months for the others. Most corporations also pay instalments during the year, monthly or quarterly.

Interest runs on a balance paid after its due date, even when the return itself is filed on time.

Source: CRA, Corporation payments.

Québec and Alberta collect their own corporate income tax, so a corporation with an establishment there files a provincial return besides its T2:

• CO-17, filed with Revenu Québec within six months after the end of the tax year.
• AT1, filed with Alberta Tax and Revenue Administration within six months after the end of the tax year.

Their balances are due on the same pattern as the federal tax: two months after the year end, three for certain Canadian-controlled private corporations.

Source: Revenu Québec, CO-17.

• T1135, Foreign Income Verification Statement: due on or before the T2's due date, when the cost of the corporation's specified foreign property was over $100,000 at any time in the year.
• T106, transactions with non-arm's length non-residents: due on the T2's due date.
• T1134, foreign affiliates: due within 10 months after the end of the corporation's tax year.
• RC4649, Country-by-Country Report: due within 12 months after the last day of the multinational group's reporting fiscal year.

Source for the T1135: CRA, Questions and answers about Form T1135.

AuraTax prepares each of these returns from the same corporation file, checks them against the CRA's and Revenu Québec's specifications before you transmit, and keeps what was sent and when, so the next year and any amendment start from it.