If you can’t pay the full amount of tax that you owe, you may be able to make a payment arrangement. If the Canada Revenue Agency determines that you cannot make a full payment, an agent can work with you to develop a plan to help you pay your tax. Even if you cannot pay all of your balance owing right away, you should still file your return by April 30th, to avoid late-filing penalties.
You can contact them at 1-888-863-8657. Their agents are available Monday to Friday (except holidays) from 7 a.m. to 11 p.m., Eastern time.