What happens if you owe money to Canada Revenue Agency 44% of Canadians may not filed their tax returns as of early April. The deadline is April 30. Here’s what happens if you owe money to Canada Revenue Agency and don’t file on time: A penalty of 5 per cent of the balance owing. An additional penalty of 1 per cent of the balance owing for every full month you’re late (up to a maximum of 12 months). Interest charged on both the balance owing and the above penalty. From there, it only gets worse. If Canadians have been charged a late-filing penalty in any of the previous three tax cycles they may have to pay a repeated late-filing penalty instead. That means: The above 5 per cent penalty of the balance owing now becomes 10 per cent. Instead of an additional 1 per cent penalty, you’re looking at 2 per cent of your balance owing for each month the return is late, up to a maximum of 20 months instead of the original 12.