In Canada, your taxes are due on April 30th. This is a hard deadline as far as the Canadian Revenue Agency (CRA) is concerned. Once it clocks over to midnight on May 1st, if you owe money then you’ll start to owe a lot more. You’ll automatically accrue 5 percent interest on your due payment, and it is compounded daily. It gets worse, as another percentage point is added each month up to a maximum of 12 months. After a year passes and if you still haven’t paid the CRA, then 10 percent interest is charged on the balance owing plus 2 percent for each full month, up to 20 months. You could see a small payment of $100 slowly balloon to thousands if you’re not careful.

Read more: Personal Investor: Missing your tax deadline could get costly