A balance owing doesn't mean you made a mistake. You may simply have paid less tax during the year than you owe. This can happen if you have two jobs, freelance income, or investment income without enough tax deducted.

Compare the income, tax deducted, and instalment payments on your return with your slips and records. If a payment is missing or a slip appears twice, correcting it may change your balance. Better Tax updates the amount as you work through your return.

If the balance looks right, you can still file your return if you need more time to pay the CRA.